the now

Survey Cooking

I seem to enjoy making surveys. Anyone that has interest in the topic of cookware, like I am, might like to submit their feedback and experience. I was surprised at how little I knew.

It’s a quick 90 second survey, check it out here:

Thanks for contributing, it is appreciated!

the now

More Summer Semester

Hopefully it was educational and interesting to read my submitted papers from my summer Human Centered Design class. I thought I would also quickly post some of the other work I produced in the summer semester that finished a couple weeks ago. (I have already begun my fall 2020 semester at the Academy this week).

Apart from the Human Centered Design class, I was also enrolled in a Digital 3d Modeling class where the rad modeling software called SolidWorks was used. I had familiarity with SolidWorks from a job and career path I began in 2001 that was unfortunately cut-short for a multitude of reasons (a subject I could probably expound upon at a later date). To experience sophisticated software evolve this much is impressive, that being said, it didn’t evolve enough to be completely foreign to me however. A couple weeks of reintroduction and I felt mostly comfortable “driving” it again. Delving into surface modeling in it was a completely new experience that did take some getting used to, but I think the end result and the final project demonstrates this well (in my opinion).

The midterm was a task to model and render a common product that was able to be dismantled, measured, and recreated in digital three-dimensional form in SolidWorks. I chose a small simple, geometric device laying around my house, the garage door opener. I think it came out just alright for something as mundane as it is. It hit all the right buttons though (pun intended): multi-part assembly, internal ribs and bosses, rendered, etc. Click the images to enjoy them more thoroughly:

Following that project was one substantially more involved using surface modeling to create a product featuring a complex compound surface. Not having an option on hand to measure and model from, we were tasked with designing a virtual reality headset. I went a direction that was unique and very organic I thought. (This was done also to satisfy the project requirement of modeling a complex compound surface in the software).

(Again, click through to fully view the images).

Developing this further I would incorporate more internal components that really lend to the model name I chose h.o.L. (for Head-on Level) including some actual user-interface display for the digital sizing and adjustments. Working out more of the draft angles and overhangs would also be wise. I initially intended on rendering it in more of a dystopian setting with the vibrant and unique color I chose as a stand-out feature compared to the predictable flat black models I’ve seen in the real world mostly. However, I think the action shot with the human model demonstrates a dynamic activity fairly well.

Being an Apple guy, I’m bummed to not be able to more readily use this awesome software for more future projects. Hopefully soon, that will change because honestly, I find it one of the more intuitive and logically based modeling software packages I’ve used yet.

the now

An Ergonomic “Rec”

During the COVID lockdown and the recent preponderance of working from home, some companies and organizations are offering incentives and financial recompense for employees to improve their at home working environment. This is a similar program to those that encourage healthy employee habits by incentivizing sports equipment and gym memberships. Keeping people apart during this pandemic is important and helpful in lowering the infection rate. One such pair of people, living together in a small apartment in San Francisco have the opportunity to benefit from a program offered by their employers. They are currently working from home as computer science engineers and have been noticing irksome ergonomic issues by their newly discovered posture while using their laptops. The female subject, named Maya for purposes of this project, typically uses her laptop on a table who’s original purpose may or may not have been a desk. It is a wide surface, supported by legs on wheels. None of the chairs she uses for this task are the right height for her. She will commonly migrate to the dining table, or the couch in order to change positions in search for comfort. The male subject, referred to as Gregory, rarely uses the table/desk surface, but more often relies solely on the dining table as a workspace, or like Maya, resorts to the couch, or even the bed for a change in posture. Maya has vocalized complaints of numbness in her legs as well as soreness and pain in her lower back. Gregory echoes similar discomfort. They are both active, healthy individuals in their early forties and are seeking an ergonomic improvement in their working from home lifestyle. They are also both avid bicyclists who proudly store their bicycles in this same living room of their small apartment. This paper and associated project aims to offer a design and ergonomic solution that may not only minimize or eliminate their laptop use discomfort, but also develop an aesthetically pleasing storage [display] solution for their bicycles by assessing their individual anthropometric geometries, compared to industry standards, and larger sample population; analysis of their space; and incorporate strategies from Norman’s Design of Everyday Things, Bridger’s Introduction to Ergonomics in creating an ergonomic and visually pleasing design.

Attempting to quantify their posture proved difficult with the pandemic lockdown of course, so effort was made to limit the timeframe of contact. A REBA assessment was performed of both Gregory and Maya in a number of their common working locations in their apartment. A REBA assessment is an analysis of the entire body posture for risk of WRMSD’s, or Work Related Musculoskeletal Disorders. REBA is an acronym that stands for Rapid Entire Body Assessment, developed by Sue Hignett and Lynn McAtamney. This is a tool for employers to conduct ergonomic surveys of employee tasks commonly utilized by industrial and commercial organizations (i.e., commercial laundry, automotive detailers, etc). While seated laptop use isn’t perhaps the most applicable task for the REBA analysis, it does still yield some telling data. The REBA assessment factors analysis of the body’s neck, abdomen, and leg positions, as well as any extremes these body parts are put into for any duration of time or additional force and load. The second half of the assessment considers the wrist, upper and lower arm positions within a specific task as well as activities and grip functions.

After performing six or so assessments, I became comfortable explaining to the subjects how some of these aspects figured into their work. Specifically how the “Activity Score” in Step 13 was considered, subjectively working with a laptop one can gauge that one or more body parts will be held for a minute or longer, this could be deemed “static” work. For leg positioning I estimated it to be in the +1 range, relaxed in a sense; taking also from the example in Bridger’s Ergonomic Workshop 4.1: legs scored a 1 as well with the note, “person is sitting”. Repeated small range actions (guiding a mouse, or track pad for example) would also score a 1. I defined the final activity score as being sudden movements or reactions that cause “rapid large range changes in posture or unstable base”—seated working on a laptop would not qualify. By comparison, I assessed my own work activity as a career bicycle mechanic and scored myself a REBA score of 15. Standing for hours at a time, reaching and twisting, applying heavy loads with tools, seeing this difference was enlightening. Performing the assessment with these two individuals provided the following scores:

 dining tabledeskcouchmechanic
Step 1: Neck Position1124
Step 2: Trunk Position2125
Step 3: Legs1133
Step 4: Posture Score A2159
Step 5: Force/Load0002
Step 6: SCORE A21511
Step 7: Upper Arm Position2115
Step 8: Lower Arm Position2222
Step 9: Wrist Position1222
Step 10: Posture Score B2228
Step 11: Coupling Score0001
Step 12: SCORE B2229
Step 13: Activity Score2223
REBA Score43615
Table 1.1: REBA scores for at home work station positions, as well as example of bicycle mechanic for comparative value
Image 1.1: One of the REBA Assessment forms filled out showing the postural analysis of the subject using a laptop while seated on their couch, scoring in the “Medium Risk” category

As the scoring system of the REBA worksheet states, these scores yield a range of risks, from the desk posture being Low Risk, “Change may be needed” to the dining table and couch spanning the Medium Risk range with the advice of “Further investigation. Change soon.” And a bicycle mechanic at the top: Very High Risk “Implement change”.

As Bridger also states, the results of a REBA analysis should be “interpreted together with data on real injury rates….” Given the above listed results, Maya, who primarily works at a desk, while being the lowest risk, however claims symptoms of lower back pain, numbness in her legs as stated, as well as discomfort in her wrists. See image 1.1, a photo of her seated at her desk demonstrates some logic to these injuries and discomforts. Her neck is within the 10-20 ̊ range, no bending or twisting, her trunk is very close to straight. Where she scores aberrantly is barely noticeable at the wrists and lower arm positions. The photo in Image 1.2 is slightly misleading as it was taken after the subject placed a thick book on the seat to raise herself; an augmentation she performs frequently she states. This observation and assessment gives confirmation to her complaints. The discomfort in her wrists can be attributable to the 15 ̊ or more incline her lower arms and wrists need to make in order for her to reach her keyboard. Without the aid of the book under her buttocks, Maya begins to feel an impingement on the underside of her thighs from the seat she typically uses (shown), over time this contributes to the numbness in her lower legs. Even with the book there is additional but different impingement that only exacerbates the numbness. This is certainly an anthropometric mismatch as

Image 1.2: While it may appear that the subject Maya has neutral posture at her desk, take note of the thick book she is sitting on.
Photo MW.

emphasized by Bridger in chapter 4, this combination of improper seating, augmented seating (with book), are increasing “the postural load on” Maya’s body. He goes on specifically, “short users may have to raise seat heights beyond popliteal height to gain access to the desk.” As her feet don’t fully contact the ground sufficiently, her legs are restricting blood flow, causing the numbness. She is also unable to stabilize her weight causing her to do so with her abdomen which may be contributing to her sore back muscles.

In an effort to find a solution for Maya and Gregory’s ergonomic challenges I approached the problem with the intention of gathering as much data as I was able to better quantify my findings. Following a select set of measurements from Human Dimension and Interior Space, I sought to build an anthropometric picture of these two subjects. These listings (in Table 1.2) each quantified a variable that might contribute to positioning their posture in a more ideal way:

Stature 1A7164
Eye Height (Standing) 1B6860.5
Sitting Height (Erect) 1D33.534
Eye Height (Sitting) 1F28.531
Elbow Height Resting 1K10.510
Thigh Clearance 1L5.55
Knee Height 1M2220
Popliteal Height 1N18.517
Buttock-Popliteal Height 1O1816.5
Buttock-Knee Height 1P21.519
Vertical Reach (Sitting) 1S47.547
Vertical Reach (Standing) 1T80.578
Table 1.2: HDIS anthropometric measurements, as well as age, of the subjects

Arming myself with other resources such as the averages developed by Henry Dreyfuss and the Humanscale sliders, I compiled some other metrics on Table 1.3, comparing these to the measured anthropometrics of the subjects shows an evident difference and deviation from the general. This is most noticeable in the Eye to Seat Height of 32.3 below compared to the 28.3” measured on Gregory for example.

HumanScale Readings based on Stature  
Easy High Reach78.971.4
Standing Elbow Height43.438.9
Leg Room Seated18.516.3
Compressed Seat Height17.515.7
Max Seat Length19.417.3
Eye to Seat32.329.2
Lumbar Height109.3
Table 1.3: Select Humanscale measurements based on average stature
Image 1.3: Humanscale Body Measurements for standing heights of 64” and 71”

Other aspects of this couple’s work from home office is what could best be described as a lack of any clear-cut office space. This is perhaps a sudden problem for many people in this state of pandemic lockdown, it is one that may or may not need to be resolved. People are now being tasked with working their jobs in an environment not necessarily suited to do so—this is certainly the case with the population that doesn’t work an office/desk job—this type of work is arguably easier to implement in the home environment better than employment as a bicycle mechanic or retail customer service as an example, however, it may be helpful for this couple to designate a work space to act as a signifier per se as to where their work from home office space should be. This not only defines the space, but also helps define when not to be working. Productivity for some people is improved if the proper mental state is achieved by stimulating familiar activities or work spaces. I have heard many stories of people getting in their car to “commute” around the block before commencing their work from home in order to kickstart their productivity. Perhaps a stretch, but this may act as a signifier and constraint in the vein of Don Norman’s Design of Everyday Things.

As the space is currently, there is only the significance of relaxation and bicycle storage in terms of areas of activity as depicted in Image 1.4 below. Their initial interest has been to find a solution to amend their ergonomic woes incorporated into this wall behind the aforementioned couch.

Image 1.4: The mid-century modern couch, cubic coffee tables, and two bicycles
Photo MW

Their current dining table sits at a height of 29” which is within the standard range of 28 – 30,” which leaves room for the legs of most adults allowing their feet to contact the floor. The desk/table that Maya commonly uses is approximately the same height. They have a several dining and side chairs of varying heights as well as a “community” bench at their dining table that is sometimes used to sit on while working. Their couch seating surface only measures 16” from the floor, while the cubic coffee tables are 17.5” tall. According to the Humanscale measurements, and Maya’s stature of 64” the maximum table height is 26.9” while Gregory’s (at 71”) tops out at 30.2”.

But where else can we determine optimal measurements, we have a population of two individuals with a considerable stature difference. Gregory is 7” taller than Maya. Comparing their statures to their popliteal heights shows a fairly close ratio:

StaturePopliteal HeightRatio

Despite their seven inch difference, they do show an approximate sitting height similarity; this could be attributable to a short or longer proportionate torso length, as well as a potential slouching despite the attempt to measure an erect, upright sitting posture. Other comparisons between the subjects demonstrate a similar proportions to their stature:

StatureElbow HeightRatio
 Sitting HeightRatio
 Eye Height StandingRatio

Calculating a workspace redesign for Maya and Gregory based solely on these numbers would be akin to a custom designed product given the minimal spread of data across merely two subjects. Considering the potential for other people using this workspace a wider population would need to be factored in. Using metrics collected from my household, as well as volunteers from class, I am able to capture a wider swath of potential users.

Out of this population, in terms of stature, Gregory is in the 89th percentile compared to Maya’s 40th. The average stature of the population is 66.51” tall. Other key metrics include the following percentiles:

 StatureElbow HeightPopliteal HeightSitting HeightEye Height Standing
Table 1.4: The subject’s percentiles for select metrics based on the wider population

These percentiles were calculated using the standard deviation of 4.41 for stature, .96 for elbow height, 1.61 for popliteal height, 2.0 with sitting height, and 4.47 for standing eye height. The wider population has an average elbow height of 9”, an average popliteal height of 17.56,” an average sitting height of 34.25,” and a standing eye height of 63.30”. These specific metric categories were selected from a basis of measurements that would directly affect posture, comfort, and ergonomic solutions as well as which categories I was able to collect samples from.

Taking the population into consideration for a solution, adjustability would be ideal, this would involve an adjustable height chair to accommodate the spreads of popliteal height of the population

So, taking the lowest percentile for elbow height out of the wider population of 8 inches coupled with the popliteal height (plus thigh height) demonstrates that the lowest a desk top surface should be is 26 inches (assuming a minimum two inches desktop thickness). This is also factoring in the chair seat height being accommodating to the 8th percentile group from this population (with a popliteal height of 14.5”). The upper percentiles would likely find this too low for them, as Gregory would no doubt discover that while his 18.5” popliteal height would put his knees a little higher than comfortable from the low seat, the height of the desk would possibly be too low and would begin to feel strain in his arms from their lack of support from the desk top. According to Bridger, “much office furniture is designed around a desk height of ~73cm” or 28.74”.

The solution for accommodating both Maya, Gregory, and the current population of this class would most likely involve an adjustable height desk chair; a range of heights would be captured within these adjustments. Something that would feature a height adjustment of the seat position primarily. Including further adjustments in arm rest height and position would be a bonus to further prevent the arms from having to support themselves. As stated in Bridger’s Introduction to Ergonomics (and the inference of extreme angles gaining negative scores on the REBA assessment) a neutral work posture is ideal. Maintaining a supported wrist and forearm implies that the joint range is being kept in a neutral position: by supporting the weight of the arms, “less load is placed on the lumbar spine”. Bridger elaborates on this point specifically when discussing “mouse-intensive tasks” as characterized by “static, non-neutral postures of the wrist and shoulder”. 

Image 1.5: Two adjustable height chair options from Herman Miller, the Aeron and Sayl models. Both feature adjustable arm rests for supporting the forearm and elbow. 
Photos from

Herman Miller Aeron or Sayl chairs for example features height adjustment from 15 inches to 19” (this model actually has a variety of sizes that have different ranges of height adjustment as well). These are both fantastic examples of a well designed, fully accommodating office chairs. Even the Aeron website product sheet states it is made for a population range of 1st to 99th percentile. Coupled with an adjustable height desk surface would enable most users to work with a comfortable, injury and fatigue-free posture. Standing desks as they are called have a height adjustment range of 25 to 50 inches. With this 66% difference in desk height, and the 23% difference in seat height range, this combination would be fully accommodative to Gregory and Maya as well as the general adult population. The additional ability to completely forgo the chair and work while standing is another option with utilizing a standing desk. Also noted in Introduction to Ergonomics, Bridger points out that, “jobs that impose a high degree of postural constraint” are ones that “require maximum flexibility” and introducing adjustable furniture is one way to compensate for that constraint. Allowing Gregory and Maya to change their working posture throughout their working day would contribute to that flexibility by giving them the opportunity to stand and sit as they deem necessary to achieve their preferred postural strategy. Providing this kind of flexibility would allow a wide array of individuals of varying anthropometric measurements utilize this workspace. Considering the desk will primarily be used for a laptop, having the ability to raise the screen to a more ergonomically beneficial position. Again, pulling from Bridger’s Introduction to Ergonomics, screen height affects posture with findings stating that a low sight line angle was the most comfortable and most quality performing. This flexibility also contributes to a less sedentary lifestyle, moving around, alternating postures (from sitting to standing) helps prevent “the formation of blood clots deep in the legs” as claimed by the Harvard Business Review (Skerrett, Patrick J. The Many Benefits of Standing at Your Desk, 30, 2010). This detriment is echoed by Bridger when discussing health hazards like restricted blood flow.

Image 1.6: The ability to alternate working posture while at a desk can minimize musculoskeletal discomforts.
Photo from

Regarding other aspects to this workspace, lighting may be an issue needing investigation. Short of conducting a strategic lighting study to determine the lux value on this desk arrangement (which might be sufficiently achieved with a simple light meter app on the smartphone of which many free versions are available), it would be worth discussing the lights currently in use. The only lights at the moment are two ceiling mounted recessed canister lights and a large paper diffused chandelier above the dining table. There is ambient light from a frosted window adjacent to the proposed wall, as well as a large sliding glass western facing window directly opposite, about 15 feet across the living room space. Efforts would need to be made to manage the amount of glare received from the overhead lighting either by augmenting them with some type of deflection or perhaps, less unsightly, replacing the bulbs with a style that offers adjustable color temperatures and dimmability to better manage productivity (by selecting a dependent on the activity). This would possibly trade the aspect of glare for the benefit of better mental focus or a relaxed mind depending on the need. Having the lights set at a high color temperature (500k +) evidently produces a cool white light that tends to “assist with focus and attention” desirable while concentrating on work, while a warm white in the 2700k range delivers a relaxing atmosphere. (Duncan, Jason. Benefits of Color-Changing LED Lighting, Jan 17, 2019). Any undue reflectance from the western-facing window could be ameliorated by drawing the curtains at those late afternoon hours. Maya’s interest in painting this wall may be opportune, currently the white wall may be providing the too much contrast to her laptop; depending on the tasks she typically conducts on the screen, a calculated color could be chosen to optimize this contrast in order to allow the “surface luminances” to gradually diminish to the surroundings as advised by Bridger.

Specific to Maya and Gregory’s work place at home, the most optimal location for this addition of a desk would be the same wall that they proudly display (and store) their primary means of exercise and transportation, their bicycles. In an effort to combine this workspace redesign, and relocating the bicycles being impossible, repositioning the bicycles is the next best idea. Utilizing the verticality of the wall, the bicycles can be stored hanging by their rear wheel in a vertical orientation. With the bicycle oriented this way, it minimizes how much it protrudes into the circulation of the room (between the wall, desk, and living room furniture) thus acting as a constraint of sorts—with the bicycle elevated this way in the sightline individuals walking will be less prone to bumping into the bicycle as they have the potential now to be literally overlooked. (This line of sight would also accentuate the bicycle frame precisely as an art piece). Another feature that could be designed in this system would also be to minimize the desk’s footprint on the floor, but incorporating the motors into the actual wall. As this couple will only be using laptops 

Instead of a simple hook on the wall, the rack itself might be designed decoratively or stylishly enough that even without a bicycle mounted on it, it would be aesthetically pleasing. This vertically mounted bike rack incidentally could afford the ability to hold other things as well, an ad hoc coat rack perhaps even. This system would feature a groove that would further constrain the bicycle to a position of laying flat against the wall.

The conceptual model of the workspace and the relaxation space, designated in order to enable a distinct break between work-life and home-life—this separation may become blurred if an external monitor is introduced. This workspace and display/storage redesign would feature numerous other fundamental principles of interaction such as the control for the standing desk, a lot of these systems are designed with a control pad that allows a programming of preferred heights. The raise/lower buttons are commonly mapped in an obvious method, with the sequence of programmed positions laid out as demonstrated in Image 1.7. As the height needs adjustment, the user merely needs to press and hold the raise/lower button until the desired height is achieved. The programmed positions provide the feedback of stopping at their pre-determined heights. Further feedback is given when the system recognizes a button is pressed by illuminating itself as well as providing a LCD measurement display.

Image 1.7: Standing desk control panel providing visual feedback. Photo MW

This desk system’s intention of alleviating a user’s ergonomic discomfort would function by the user accepting and understanding the initial conceptual model of the desk as a workspace. For Gregory and Maya, this is fundamental knowledge in their heads, the workspace confirms this as being the knowledge in the world. Opening their laptop and commencing their work tasks (attempting to achieve their goal of being productive), performing their coding, writing, or designing tasks is executed as expected. As their work day progresses, as the minutes tick by Maya gradually begins feeling a discomfort in her wrists, or her back, perceiving and interpreting this discomfort, for example with her new standing desk, now has the ability to change her working posture by changing the height of her desk. This enables her to continue being productive without expected aches and pains. In likely a short period of time, these adjustments will become almost a subconscious activity. This process could potentially become even more subconscious through an automation in the desk raising. For instance, after a predetermined time period, programmed by the users, the desk could provide a signal that would recommend Gregory or Maya to change positions, avoiding the tendency to remain in an uncomfortable or potentially injurious posture. One element to some of these control boards that may be lacking is a tactile feedback, a smooth and flat surface appears nicely designed, but including a raised ridge on each button would be helpful in activating them quicker.

Regarding the user interaction with the bicycle racks, again, the knowledge of their purpose would exist in Gregory and Maya’s heads. But what about potentially new tenants to this apartment that may not receive a direct walk-through from “those in the know”. How would they learn what these artistic, perhaps oddly spaced for, coat-racks? Some type of ornament could be included in the aesthetic design to signify their purpose would be a solution. A subtle, embossed image of a bicycle perhaps—aesthetically placed “knowledge in the world”. 

The actual shape of the bicycle hanging system could be a vertical member that would extend from the wall a couple inches at most, from this an arm would protrude from the upper portion and this would feature a groove that the user’s bicycle wheel would rest in, supporting the weight of the bicycle hanging below. This groove would be a modular component to allow a user to switch out depending on the width of their bicycle’s wheel. (There could be numerous versions of this component available for customizing the system in a multitude of ways even by each having a different angle even to accommodate different shape and sizes of handlebars). Along the vertical member mounted to the wall, should include another, lower protruding arm to stabilize the bicycle as it hangs to constrain it from swinging. Further constraints might be designed to prevent a user from accidentally “missing” the groove and dropping the bicycle. This would be akin to Norman’s forcing function: “the actions constrained so that failure [the bicycle not being secure in the groove] prevents the next step from happening [walking away after hanging the bicycle]” (Norman, Don. The Design of Everyday Things. Basic Books, 2013). How to constrain a user from walking away without securing the frame to the lower stabilizing support will require further creativity.

Image 1.8: Conceptual sketch of bicycle storage hook system. Design MW

In summary, if Maya and Gregory were to use their casual and dining chairs for their intended purpose and invest in a height adjustable desk and office chair, their anthropometric mismatched issues would be remedied. Given the limited dimensions of their apartment, the most suitable solution would be to utilize the wall they are currently using as their bicycle storage location, appealing to their love of bicycles, minimizing the footprint of the bicycles by hanging them on the wall would allow for greater ease of circulation, as well as indirectly demarcate the workspace from the living/relaxation spaces. Further minimizing the footprint of the workspace as to limit “work-time” encroachment on their “home-time” creating a custom standing desk with limited depth would further maximize their “home-space”.

Image 1.9: Conceptual sketch of wall re-design showing internally mounted standing desk, book shelves, and bicycle storage hanging positions. Design MW
Table 1.9: Layout of calculations and sample data



Norman, Don. The Design of Everyday Things. Basic Books, 2013

Bridger, R.S. Introduction to Ergonomics, Third Edition. CRC Press, 2009.

Diffrient, Tilley, Bardagjy. Humanscale 1/2/3 Manual. IA Collaborative Ventures LLC, 2017/1974

Panero & Zelnik Human Dimension & Interior Space. Whitney Library of Design, 1979

Sue Hignett􏰎, Lynn McAtamney􏰏. Technical Note, Rapid Entire Body Assessment (REBA), Applied Ergonomics 31, 2000 


Skerrett, Patrick J. The Many Benefits of Standing at Your Desk.

Duncan, Jason, Benefits of Color-Changing LED Lighting.

the now

BART 9.2

Evidently tourists occasionally embark the incorrect BART train because of the aesthetic band of color located on the trains themselves. Specifically the Dublin/Pleasanton line which is designated with a blue color on the BART transit maps. All of the trains have this similar color on them which incorrectly leads an unfamiliar tourist to get on an unintended train.

Graciously linked from

This is a situation that describes unreliable, or misleading, signifiers. It sounds like these passengers are misinterpreting an aesthetic augmentation (the blue stripes), for a signifying label. I have ridden BART only a handful of times, and don’t entirely remember what the trains look like, but I would assume the stripes on the train are lacking sufficient differentiation from what [the passengers] are using as their conceptual model of the train line indicators. I would qualify this error as a mistake, and not just a slip, because of this fact—the passengers have an incorrect conceptual model of how the trains are labeled. It isn’t simply an action-based slip because, while the intention was to do one action, and another was performed, the one action was formed by an incorrect plan: get on the train with the blue in order to get on the Dublin/Pleasanton line. It also feels like what Don Norman calls a “knowledge-based mistake” (184), especially with the statement that those who most frequently have this confusion are “tourists”. These are people that, as he states, do not “have a good understanding of the situation,” Their conceptual model, of the familiar task of selecting and boarding their train, is incorrect in this new, novel, environment. 

Applying a root cause analysis (perhaps in an opposite way), an accident might not be likely, but extrapolating the situation where someone needs to satisfy an emergency at a specific location on the Dublin/Pleasanton line, and thus missing the train to that location could result in an accident. Simply put, a missed appointment, could result in an accident. 

Also graciously linked from

Some quick design solutions might entail re-doing the aesthetic painted stripes on the trains to include all of the colors that represent the train lines. This may have the result of forcing the passengers to look elsewhere for the train demarkation, and dispel any assumptions. If all of BART’s line colors are represented, that might prevent the assumption outright. Another solution might involve better mapping on the actual train line map that these passengers would ordinarily use to choose their desired line. Perhaps the  legend could include a representation of where to look on the actual train to determine which line it is. If the stripes were contoured in a way that drew the observer’s eyes upwards from knee-height to the train line’s destination sign/color. Associating each line with a different symbol would also better differentiate between them; this might also have the added benefit of aiding the color-blind. Including some form of feedback, like an audible notice of what train they have just entered may be helpful, although may result in more ignorable “noise” in the system.

the now

Mistake(s) 9.1

The Warehouse in the Industrial Design building loans out a variety of tools to students and specifically to this entry, end-mills are loaned out for the metal shop machines. As an example, the mistake that I have observed has resulted in broken end-mills and increased the potential for injury.

As they are cutting into the material, SNAP! goes the end-mill, and hopefully everyone in the vicinity has their eye-protection on.

Was it a mistake? Perhaps a memory-lapse mistake, the student may have not installed the tool correctly in the machine due to being distracted in a conversation with a friend. This is also a rule-based mistake, as the shop policy states that every student has agreed to include not being distracted using the machines.

Could it have been a slip as well? Likely also a memory-lapse slip, even if alone in the workshop, one step of the procedure could have merely slipped their mind.  

The most significant mistake is as follows, a regular confluence of errors. It goes like this: the student needs to borrow an end-mill from the tool crib, students are frequently inexperienced in using the tools, have only a limited understanding of terminology, and perhaps even have a language hurdle. They make their verbal request, are given a tool, and off they go. SNAP!

This time they were given the incorrect tool. This could be a rule-based mistake on the part of the technicians working in the tool crib, and perhaps a knowledge-based mistake on the part of the student. The student did not request the correct tool, and the technician did not verify that they provided the correct tool.

Better reasoning needs to be applied at the point of tool delivery in my opinion. Deductive reasoning applied to a conversation (a brief series of questions) that the technician begins when the student has a tool request. Deducing, from the series of answers, what exactly the student needs, as well as, potentially how experienced the student is. This conversation could potentially act as a constraint to prevent incorrect tool acquisition and in turn, prevent incorrect tool usage. 

the now

Coffee Debate

Back to my coffee; I brew a French press pot every morning; without which I have neither long-term, nor short-term memory. There’s an insignificant point of dispute in my household regarding the method of measuring the amount of coffee. Both my housemate and I remember (with the long term memory and knowledge in our heads) that our optimal coffee robustness requires 30grams of coffee; I have repurposed this gram scale from my bicycle workshop to achieve this amount. It is the method of weighing this value is the point of dispute. She claims it is more efficient to weigh the 30g in the same vessel the coffee is ground into. In an effort to “conform” I wrote the tare weight of the receptacle on the bottom, in order to precisely weigh the optimal 30g. This is an example of me putting the memory in the world, accessing knowledge in the world. This is obviously one too many numbers for me to have to retain and recall while bleary eyed in the morning, which is only part of my logic for weighing the coffee grinds the way I do. I merely place the coffee pot on the scale, press the tare button, and dump the coffee into the pot until it reads 30g. I have no idea how much my French press pot weighs, I don’t care. The scale is providing me the tare, this is my knowledge in the world. Sometimes I am not careful and accidentally pour too much in, to the point that up to 36g of coffee is brewed. (This is not a problem, it still drinks, albeit a little harsher). What does the housemate do when she has accidentally ground too much, and the receptacle on the scale reads 120 grams instead of the 116g as it is supposed to? How much does she pour into the pot? 

But this is the heart of the dispute in my mind though, the coffee grinder itself lacks sufficient constraints. There is no physical constraint preventing over or under grinding, or even any indexing on the graduations of the grind dial. Did I rotate the dial exactly to “3”? Was it over or under? The mapping is demonstrating the conceptual model that “1” on the dial indicates 10 grams. But without any of the tactile feel at each graduation, there is little precise feedback. When I pour in the grinds and it only reads 28g, this must be rectified! So I put the grounds receptacle back in, and give the dial a nudge, again, there’s no graduations for single grams, so I usually have to nudge it a few more times. If I nudge too far, it’s sure to over grind too much. The dial has graduations on it “0 – 10” and when turned, it activates the grinder and slowly winds itself back to “0” much like an analog kitchen timer; from our experience, dialing “3” yields 30g of coffee. This is a logical constraint, but by the lack of the physical indexing in the dial—tactile stops at each graduation—I would qualify it as loosely logical. (It is also a logical constraint as to where the ground coffee receptacle resides on the grinder, as it is the only place it will fit). 

We also have several other forms of coffee brewing that we enjoy in our house. The fantastic Bialetti stovetop espresso. (The only cultural constraint using this device is an air of European snobbery is suddenly required.) Beyond that, its role in this entry is its demand for finer ground coffee. Which our grinder affords, the ability to produce a wide spectrum of varying coarseness. At the bottom ring of the bean hopper is the grind adjustment ring, which does provide adequate feedback in knowing what grind setting it is in, by the indexing tactile feel. This adjustment is another problem as well. On the occasions we make stovetop espresso, our newly adopted laissez-faire attitude prevents us from remembering to return the grinder to the optimal setting for French press. At which point the next morning, we grind 30+ grams of powder, unusable for the press.

It would help if the grinder had a more prominent indicator, or signifier, of what grind setting it was set to; helping further would be some type of reminder constraint, an interlock force function that verified volume of grind (perhaps even with a built in scale) and coarseness of grind before starting.

the now

A Shelf Too High

Looking specifically to my kitchen that I have been using for the past three years, I have come to a proper understanding of why it works the way it does. There are certain elements to it that work only adequately, others that could be improved upon, and others that I have learned to live with. I make the assumption that this is the case with most things that we interact with over a similar period of time. Much like Don Norman writes about in chapter three of his seminal work the Design of Everyday Things, much of how my kitchen functions has become knowledge in my mind. There were no user manuals for these functions; this knowledge and understanding was attained by discovering what was possible to perform an edible meal in this kitchen.

Take the countertop, a common enough feature of a kitchen. So common that its function affords many things and its conceptual model is likely defined in everyone’s mind. The countertop in my kitchen is not level, but it is about the standard height of 36” from the floor, according to Bob Vila and the American National Standards Institute Reddigari, Manasa and Vila, Bob. “Solved! Figuring Out the Correct Countertop Height for Your Renovation.” At this approximate 36” height, my countertop affords the ability to store clutter primarily, but it acts as a work space for school projects sometimes, as well as it’s likely intended use of a food preparation surface. Associated to the one element that really doesn’t work well in this kitchen, the countertop also affords the function of being a dangerous step stool. When I need to access anything on the cabinet’s top shelf, I can clamber onto the countertop and stand on it to reach.

The Kitchen in Question

Speaking of those cabinets, they look clean and modernly unadorned in a fancy-design way from the late 1970’s perhaps, but they offer no signifier of how to actually open them. Nor do the drawers with their similar modern façade. The primary signifier for opening any door is typically some kind of handle, or knob, perhaps a label in the worst of scenarios, “When external signifiers—signs—have to be added to something as simple as a door, it indicates bad design.” Norman, Don. The Design of Everyday Things. Basic Books, 2013. The only visual signifier for these cabinets are the hinges, which are significant enough, especially when coupled with the conceptual model of the common kitchen. One expects cabinets, or shelving of some sort in a kitchen, so what else besides a cabinet could those hinges be indicating. One is forced to search for the aspect of the cabinet door that allows a user to open it. The search results in the tactile discovery of a groove on the top of only some of the drawers, where the groove is absent on the top, it is found on the bottom. Every cabinet has the handle groove on both the top and the bottom of the door. I have yet to consistently access the bottom handle grooved drawers “correctly” to this day, instead this design has the ability to be pried open regardless while affording the scraping of paint underneath ones fingernails. Somehow I have learned to live with this. This selective grooving of the handles being on the top and bottom is likely for the cabinet installers to not need be so specific on which side to place the hinges, it affords them the ability to get their job done more efficiently. I don’t personally see any problem if the grooves were equally democratic on the drawers as well—why not provide the affordance of opening the drawers by the top and the bottom edge?

Top without, Lower Drawer with
Drawer without, Cabinet with 

One feature that I do find quite positive with the cabinets is the storage they provide. They afford the ability to contain foodstuffs, cooking devices, dining utensils. This storage aspect of them completely fulfills the conceptual model I have in my mind regarding cabinets and drawers. I have discovered and put knowledge in my mind concerning one aspect of a specific cabinet in this kitchen of mine. The one across from the dishwashing machine. This specific cabinet actually contains two open-topped drawers. There is a sudden confluence of inaccessibility if the dishwashing machine happens to be open, the cabinet is prevented from opening completely thus limiting the access to the drawers inside. The knowledge in my mind that has developed is an order of operations must be executed to successfully navigate this process—never mind the quagmire encountered if the oven door and adjacent bottom drawer is also open at the same time. 

Cabinet & Drawer Potential
Thwarted by Dishwasher
Complete Disaster

My stove top is glass it’s had a chip in it since before we moved in, the landlord doesn’t think it’s a problem; beyond its primary function of heating things it also affords the ability to be close to perfectly flat, which affords another “knowledge of the mind” solution. As is evident the countertop is tiled which doesn’t afford the ability for a consistently flat surface, using a cutting board on the tile results in a lot of unstable cutting. I will frequently perform my food prep, cutting of vegetables and such with the cutting board on the glass stove top for improved slicing. In terms of anthropometry, our 36.25” countertop is actually a little too short for my housemate and I. Food prep is a little fatiguing, the cutting board on the stove top helps a bit, but we have found that raising it even further by stacking it on a second cutting board and long trivet help the most. This raises the cutting surface an additional 3” as well as affords a more stable cutting surface.

There are other features in this kitchen of course, too many little appliances, an archaic double sink with a faucet that has a generally accurate mapping of hot and cold controls: rotate it in the direction of the red out comes hot water, towards blue the user gets cold water. This faucet also has a wide spray function with an internal constraint that returns the water flow back to regular aerated water when the valve is closed. The sink is archaic because the secondary sink is strictly for the garbage disposal. Disposals in general have a curious constraint typically designed in their installation. The wall switch for activating the disposal is usually a considerable distance away from the sink, this prevents a user from accidentally grinding their hand as they activate the device. Back to the stove where the knowledge in the world that Frigidaire thought to include by mapping the burner controls linearly on the face of the appliance. To this day, I have yet to retain that mapped knowledge to become knowledge in my mind. Perhaps it’s the additional options of the Bridge Element, the Large & Small Elements on one single control, as well as the Warming Zone control and missing Warming Drawer dial. As Norman explains at length in chapter 3 as well, simply realigning the controls for the two rear burner elements above the two front controls (in a similar spatial configuration as the burners) would result in me never having to carefully pause and look at which knob I need to turn for the burner I want. Fortunately, what I have put in as knowledge in my head is the expected feedback from which burner is on. The glass stove top shows a red glow as the heating element is active. There is also a Hot Surface light that remains illuminated until all the burners have cooled to a safe temperature.

Linearly, and Poorly, Mapped Burner Controls
Large Element On
Hot Surface Light Indication

As mentioned earlier, the one element that really doesn’t work in this kitchen are the top shelves in the cabinets. These measure about 85” well beyond either mine or my housemate’s reach. Using a chair from the dining area works, but is pretty dangerous considering the wood floor and sculpted plastic, non-flat sitting surface of these Herman Miller knock-off chairs. Clambering on to the countertop surface is another  solution, albeit equally dangerous, not to mention less than sanitary. Since kitchens are being designed to accommodate a wide swath of the population, it makes sense to maximize the storage potential in them, thus the evidence of many kitchen’s shelves vertiginous height.

Height of Highest Shelf in Cabinets

Kitchen cabinet systems capable of total adjustability to accommodate the human dimension of the individual user,” as stated by Panero & Zelnik Human Dimension & Interior Space. Whitney Library of Design, 1979.I believe this is what is some of what inspires the adjustability in the shelves of most cabinets, the variety of holes and moveable pegs to set the desired height of shelf locations. However, this still  produces unreachable or unusable spaces in our cabinets. The solution isn’t to lower the shelves, but to rather ensure that same population and their widely varied stature are more easily able to access and utilize these high shelves. My suggestion for interior designers, architects, and cabinet manufacturers is to include a built in and seamless ladder solution where the stature of all kitchen users is not known. Where space is limited, not all users can have a convenient storage for a ladder or step stool, so why not have them built in and discreetly stored but conveniently accessed like the numerous solutions depicted here.

Taking the anthropometric data of stature as delivered in previous modules, and determining our Easy Overhead Reach from the Humanscale charts Diffrient, Tilley, Bardagjy, Humanscale 1/2/3 IA Collaborateive Ventures, 2017/1974 (which are averages based on adult standing height), and comparing them by physically measuring our Vertical Grip Reach using the method detailed in Panero and Zelnik’s Human Dimension & Interior Space. Produced the following numbers:

 StatureEasy High ReachVertical Grip Reach
MW:70.25” 77.90” 84.00”
RZ:66.00” 73.70” 85.50”
SP:59.00” 65.60” 71.00”

As could probably be easily determined, the average number that the Humanscale charts are rather general. Compared to the actual data taken from physical measurements, as described by HDIS, the data can be rather different:

StatureVertical Grip ReachRatio
70.25” 84.00” 0.83631
66.00” 85.50” 0.77193
59.00” 71.00” 0.83099
71.00” 95.00” 0.74737
65.70” 85.00” 0.77294
66.90” 86.10” 0.77700
68.00” 92.80” 0.73276
66.00” 79.00” 0.83544
61.20” 72.00” 0.85000
64.80” 76.80” 0.84375
71.50” 84.50” 0.84615
69.50” 84.00” 0.82738

This variance in ratios indicates perhaps a more realistic calculation, but could also indicate inconsistencies in measurements. 

Taking the three of our statures and reach numbers, the ratio and proportion are equated to be pretty similar:

 Stature Easy High ReachRatio 
MW: 70.25” 77.90”0.90180
RZ: 66.00”73.70” 0.89552
SP: 59.00” 65.50” 0.90076

Rounding to the nearest 100th, puts these numbers approximately equal at .90. 

Taking this data further, and factoring in more of our individual housemates and such, provides a larger sample snapshot, which appears to emphasize that proportion between reach and stature is fairly consistent:

Stature Easy High ReachRatio
70.25”77.90” 0.90180
66.00” 73.70” 0.89552
59.00” 65.50” 0.90076
71.00” 78.90” 0.89987
65.70” 73.70” 0.89145
66.90” 74.70” 0.89558
68.00” 75.90” 0.89592
66.00” 73.70” 0.89552
61.20” 67.90” 0.90133
64.80” 72.60” 0.89256
71.50” 79.90” 0.89487
69.50” 77.00” 0.90260
Adjustable Page from Humanscale Depicting Numerous Anthropometric Values and the Easy High Reach


St. Dev:5.683.80

From our three households, our sample stature produces a mean of 66.65” a standard deviation of 3.80. Across all three students this calculates to a mean of 65.08”, and standard deviation of 5.68. Using our household data will demonstrate more refinement in the numbers. 

The 90th percentile stature in our cumulative households is 71.51”, where the 10th percentile is 61.77”. The population in the 90th may have an Easy High Reach range that would more easily reach that top shelf height.

Out of our households I am in the 82nd percentile for stature with a z-score of .1814, 55th percentile for Vertical Reach with a z-score of .4483, and in the 80th for the average Easy High Reach.

The population that is above the 87th percentile for height should be able to adequately reach, this individual from our sample is also in the 91st percentile for Easy Reach, and 58th for Vertical Grip Reach. 

So taking this data, and our potential of a built in step stool or ladder solution, how much lift would we need to put more of our population into “arm’s reach” of that top shelf? 

Bringing our population’s lowest stature, in the 14th percentile, into the 87th percentile (still accounting for arm reach), would require adding about 12 or so inches to their height. One of the solutions proposed earlier would handily accommodate this improved reach and then some. The Hideaway Step 180 offers an additional 15.25” of vertical height. This would equate to a 26% change in stature effectively putting them in the 95th percentile for stature among these households. A user’s Easy High Reach could be estimated to have a difference of 81% reach, however, accounting for the arm length (estimated by the averages produced on the Humanscale dials) the 14th percentile person may have an arm reach shorter by 5.7” that the person in the 95th percentile by stature. 

I propose that a discreet solution for raising the reaching ability of the population be more frequently implemented in kitchen design from the start. Apartments and houses change residents all the time, this is a constantly fluctuating population considering rental properties, why not accommodate more people?



Norman, Don. The Design of Everyday Things. Basic Books, 2013

Bridger, R.S. Introduction to Ergonomics, Third Edition. CRC Press, 2009.

Diffrient, Tilley, Bardagjy. Humanscale 1/2/3 Manual. IA Collaborative Ventures LLC, 2017/1974

Panero & Zelnik Human Dimension & Interior Space. Whitney Library of Design, 1979


Reddigari, Manasa and Vila, Bob. “Solved! Figuring Out the Correct Countertop Height for Your Renovation.”

All photo credits are by the author except where noted by a URL. Details of which are as follows: copyright 2013 marilyn peryer photography

the now

Academy Art U News

Got a quick mention in the Academy of Art University newspaper that was just posted. A couple weeks ago I was interviewed for the Future Now event I was a part of. Here’s a link to the article:

Pitching to the Pros By Nina Tabios

The interview was an appreciated reminder of the honor I felt of my project being included with other well designed projects. While I wasn’t selected to actually pitch my idea to the judges, I was ready to promote the concepts of sustainability (by using off-cuts of recyclable materials), marketability (associating the ‘Pelago Platform with [Oru Kayak‘s] successful brand specific design language), community building (connecting like-minded people together), portability (handily foldable and compact) and usability (a simple strap and clip system for implementation). If given the opportunity, I’d love to receive feedback as well from the judges on this project….

Highlighting my inspiration of the kayak protests in Seattle seems apropos in this time of civil strife the country is going through now. While social distancing is recommended to keep the pandemic contained, hopefully one day soon, the ‘Pelago Platform can be brought to fruition to bring us together in peace.

the now

Ergonomics Diary 2

Every morning I make a French press pot of coffee and have gone through a number of different devices for boiling water over the years. They eventually short out or lose accuracy in their thermostat and thus need replacement. This latest one is the most simple I’ve had yet: The Müeller Ultra Kettle!

At first glance, it is obvious that this is a vessel that affords holding and pouring liquid water by the evidence of the spout and handle signifiers. Given the base it rests upon and the electric cord to the wall, a quick conceptual model of this device alludes to it being a kettle for boiling water. (Granted, it did not arrive in its box full of water). 

The graduated markings on the side of the glass signifies the recommended constraints of overfilling the kettle.

The interaction of this device begins with filling it with water, the first step to achieve this utilizes what I find a little vague despite the rather prominent signifier of the button on the top: 

Perhaps a little indirect, as one of the mapping elements is located underneath the kettle, but through tactile feedback, a user will be able to correctly place the kettle on its base by the circular heating element as it interfaces with a female receiver underneath. If this wasn’t placed correctly, the user would quickly get the feedback of the kettle likely toppling to the counter and not sitting stable on the base. The next step in attaining hot water, after setting the kettle, full of water, correctly on the base, is to press the switch on the handle. The protruding boss on the handle acts as a signifier for the button. This immediately provides the feedback with the visible blue light and the click of the switch and auditory rumble of the electric heat being applied to the element.

This is one of the features that is different from previous models of kettle I’ve had. This one features a single simple button. Other versions had a bank of buttons mapped to specific temperatures/drinks (i.e. 195˚/oolong tea). I personally am not that refined of a hot beverage drinker, I just want the water temperature to be hot for making coffee, so like Don Norman talks about on page 59, I have formed a story that the individual temperature settings are merely vaguely different degrees of a rolling boil. This is an outcome I do not need. (This lack of boiling difference was due to the fact the thermostat in that previous model died which ultimately showed me that my conceptual model of those varied buttons was incorrect—I was blaming the wrong thing). The next feedback received is given when  the water has reached completion in temperature. The blue light turns off and there is another audible click of the switch releasing back to the off position. At this point another interactive constraint has been put into effect: the heating element also turns off, preventing any accidental over-boiling and steaming off the water and scorching the kettle to the point of ruin.

Adding to this diary entry I sought to directly consider Don Norman’s Fundamental Design Principles listed on page 72 of DOET, this kettle actually seems to satisfy them, take for instance the following: 

Discoverability—it is pretty evident immediately what actions are possible: open lid, fill with water, press button to heat water, lift kettle, and pour hot water

Feedback—given the clear glass of the kettle, there is immediate feedback to the volume of liquid contained therein, whence full, and button pressed, the visual feedback of the blue light indicates an action has been executed (water is getting heated); further feedback upon completion is fairly evident as well as the blue light turns off when the water has reached the point of boil

Conceptual Model—the kettle being a common enough kitchen tool provides the concept clearly enough that filling it with liquid and activating the heating element is obvious

Affordances—apart from the initial affordance of holding liquid, (also any liquid for that matter—heating loose leaf tea could also be performed which might also  be benefitted by the filter screen at the spout), more simple affordances could be watering houseplants, or awkwardly drinking directly from the kettle all exist

Signifiers—the designers of this kettle made sure to include the obvious signifiers of the button to activate the heating element, as well as the opening mechanism not to overlook the direction of the pour spout being opposite that of the handle (to give a nod to the popular cover of DOET), but also, as mentioned the graduations on the glass to signify volume of liquid 

Mappings—the most obvious relationship between controls and their actions related to the spatial layout of the kettle exists between the interface of the electrical heating element on the base and underside of the kettle

Constraints—logical constraints exist with this specific kettle in how it turns off on it’s own to prevent boil dry conditions as well as the potential affordance of heating loose leaf tea where the spout filter screen would physically prevent tea leaves from entering the drinking cup

the now

Ergonomics Diary 1

Perhaps too literal, but this acrylic sign posted at a small neighborhood development provides an easy mapping of the convoluted organization of the condo units. This map is a convenience for delivery drivers (of which there is an abundance of different unfamiliar faces now) to find exactly which unit the package they are delivering needs to go. As the lost individual stands at the “YOU ARE HERE” location in the real world, they should be able to more readily determine where to go by the “spatial correspondence between [the map’s] layout” of the addresses and the addresses they need to deliver to. I believe there is also an argument that the “YOU ARE HERE” even provides a basic conceptual model to observers of the development’s layout. Similar to Norman’s description on page 21 of vehicle controls having “a compelling conceptual model of the how the operation of the control affects the vehicle”.

Similar to an example found in Design of Everyday Things, I snapped this photo several months ago of the Industrial Design Warehouse lockers. It is showing the top of the locker bank affording the ability to support other objects (despite signs advising the contrary). As also described in the book, the disregarding of those signs acted as a signifier that it was a place to put a coffee, boxes, materials, and other supplies. An example on page 18 describes, these “accidental affordances can become strong signifiers”. Perhaps the signs the administration posted weren’t as significant as intended?

This image of my shower water control is one that I manage to continually be confused about. As an example of bad feedback, a bleary-eyed and foggy-brained in the morning, I don’t frequently examine which direction to turn the center handle for comfortable water. Upon further examination of the color coding (signifiers of temperature), the direction of rotation functions in the opposite of what I personally find intuitive. The colored arcs are more akin to directional arrows instead of adjustment of temperature. The wider section of the colored arrow doesn’t indicate more cold (blue) or more hot (red), but the opposite. It is instead the narrow section is indicating the user to rotate in that direction for more cold, or more hot. Feedback communicates the results of an action as stated on page 23 of DOET and “even a delay of a tenth of a second can be disconcerting” or scalding as the case may be with this faucet handle.

An example of a constraint I have enjoyed  examining is shown in this image of a tin of edible mints. Different from the typical Tic Tac container this lid features a child-proof mechanism that constrains less dextrous hands from opening it. The dexterity involved requires a considerable pinching force on the two symmetrical tabs on the side, while leveraging the top flap open with a fingernail on the short side.  This constraint seems obvious in that it directly controls who can open the container—at least to a degree. This type of child-proofing does have potential limitations, possibly with an adult suffering from arthritis. If this seems too specific, I think if we look at society at large as the user, the constraint makes more sense in that it is “preventing the human error” of under-aged population ingesting potentially harmful chemicals. Following through with other aspects of this design is also the fact that there are no instructions or markings provided telling the user how to open the container, the protruding tabs and front edge slot are the only signifiers of how to crack this vessel  open.

This Frigidaire dehumidifier has a few examples of these Principles of Interaction. The recessed cavity that is approximately the width of an adult hand is a signifier that brings a user to the affordance of the device’s portability by it’s slide-out handle. The presence of this handle is the signifier which “communicates how to use” this product—how to move this product specifically. There is even evidence of unintentional significance in the “on-off” button shown by the wear marks on the plastic. The six buttons themselves are  also mapped to their respective indicator lights directly above them. Imagine how confusing this dehumidifier would be with that alignment? 

Another example of a feedback interaction was this error I received just this week when attempting to install this SolidWorks software. Not knowing enough about the application’s licensing procedure (or the Windows Operating System for that matter. I was left helpless without a clue as to what my next steps would ned to be to successfully install this software. After clicking “OK” the installer merely quit with little guidance or definition as to how to “obtain a license” nor what a “Server node” is. This is admittedly a separate issue, like Don Norman states on page 23, “Feedback must also be informative,” the installer system did at least provide some explanation; my issue was that it was effectively in a different language that I didn’t understand. 

My initial thought regarding a system image is taken from my experience working on and selling bicycles in a retail shop. Many times over I had the experience of witnessing an about-to-be-owner of a brand new bike expressing legitimate shock that the purchase price they are preparing the put down would not be the last amount of money they would need to spend on “bicycle”. I state it that way because to me, their system image of bicycle ownership was just that simple. There was frequent surprised reactions when they were informed that regular maintenance and up-keep that cost money down the road. Their system image did not include that, nor the wearing down of components, accidental flat tires, security, upgrades etc; it merely consisted of the pleasure of riding their bicycle. I always hated the feeling of being a joy-kill when I informed them of my system image of “bicycle”.