Why Engineering Psychology is Important

Writing my last blog post, I wanted to think of something that would capture why engineering psychology is important. I started this blog series by talking about what engineering psychology is and I want to conclude with why it is important.

Poorly designed ergonomics can cost lives. That is why it matters. One recent example is Anton Yelchin’s death on June 19th, 2016. According to CNN, Star Trek actor Anton Yelchin exited his vehicle and his “car slid backwards and pinned him against a brick pillar and a security fence, causing trauma that led to his death” (Visser, S., & Hassan, C. 2016). Unfortunately, Yelchin’s death was entirely preventable. He lost his life due to poor ergonomic design.

Yelchin was driving a 2015 Jeep Grand Cherokee which was actually recalled because it had a tendency to roll away (which was linked to its shifter). One article I found on Jalopnik discusses many of the problems with shifter that killed Yelchin.

Tracy, D. (2016, June 21). The Jeep Shifter [Shows the 2015 Jeep Grand Cherokee Shifter]. Retrieved April 25, 2018, from https://jalopnik.com/heres-the-problem-with-jeeps-recalled-gear-shifter-1782364420

The bad ergonomics in this design are that, unlike other shifters, this design does not press and stay in position. It sort of gets bumped up and down and engages the gear then returns to its original position in the middle. This behavior makes it difficult to know what gear is currently engaged which may be why Yelchin ran himself over. Had he known that the car was in neutral he would have switched the car to park prior to exiting the vehicle.

In fact, the National Highway Traffic Safety Administration complained about this gear shift design saying: “…operation of the Monostable shifter is not intuitive and provides poor tactile and visual feedback to the driver, increasing the potential for unintended gear selection.”

The point of this story of Yelchin’s death is to illustrate why engineering psychology is important. Many factors were at play when Yelchin died but many of them were preventable. The design is clearly flawed. The user does not have enough signifiers to know which gear the car is in. And the car only briefly says which gear the car is in and that only happens when the user actively switches gears. This death is preventable and so are many more through better engineering psychology.

Engineering psychology is relevant in every field and every process that involves humans. Therefore, every field and every process can be improved with engineering psychology. In factories, understanding how humans work on the assembly lines can lead to safer standards and better work practices. In driving, ergonomics can be used to make drivers safer and facilitate that process better. In medicine, engineering psychology can keep prevent misuse of equipment and better regulations. Every field can benefit from engineering psychology.

Yelchin’s death is one of many that can be prevented with better ergonomics. It matters because people matter. People are hard to understand but its necessary to keep them safe. That is why engineering psychology matters.



Visser, S., & Hassan, C. (2016, June 20). ‘Star Trek’ actor Anton Yelchin dies. Retrieved April 25, 2018, from https://www.cnn.com/2016/06/19/entertainment/actor-anton-yelchin-killed/index.html


Tracy, D. (2016, June 21). Here’s The Problem With Jeep’s Recalled Gear Shifter . Retrieved from https://jalopnik.com/heres-the-problem-with-jeeps-recalled-gear-shifter-1782364420


Tracy, D. (2016, June 21). The Jeep Shifter [Shows the 2015 Jeep Grand Cherokee Shifter]. Retrieved April 25, 2018, from https://jalopnik.com/heres-the-problem-with-jeeps-recalled-gear-shifter-1782364420

Standing Desks

Figure 1: Kelly, J. (2014, June 24). Proper Height Of Standing Desks [Proper Height Of Standing Desks]. Retrieved April 19, 2018, from https://notsitting.com/proper-height/

Recently during office hours, my calculus professor showed us her brand new toy – a standing desk. She looked at us, her pupils, with pride and joy as she raised and lowered her desk at the press of a button. Basking in our ooohs and ahhhs of admiration she explained to us that the desk is useful because it prevents her from sitting during the long skype calls that she frequently finds herself on.

This experience made me start thinking about the ergonomics of standing desks. What are they useful for? How do they help? I wanted to find out because as a college student I often find myself sitting for long periods of time without break.

According to one article I found, there are many negative health risks associated with sitting for long periods of time. According to the authors Roberto M. Benzo, Allene L. Gremaud, Matthew Jerome and Lucas J. Carr at the Department of Health and Human Physiology at the University of Iowa, the average person over the age of six in the United States spends 7.7 hours a day engaging in sedentary behaviors. The study found that students and professors were overall in favor of using standing desks over sitting desks most notably citing perceived increases in attention and physical health.

From an ergonomics standpoint, if students and professors are better able to complete their jobs with the assistance of standing desks, then classrooms should be designed to incorporate these desks. Ergonomics is about making the world easier and safer for people. There are serious health risks involved in prolonged periods of sitting. Unfortunately, the education system largely requires that students be present in one location and listen to another person talk in order to learn. Due to that parameter, it becomes the job of human factors engineers to design the system to accommodate that issue. This study believes that the solution may be standing desks.

According to my second article, the effects of standing desks may be mixed. The authors conducted a study on if the accuracy of movement is greater when standing or sitting. They had adults and children try accurately drawing while both standing and sitting and compared the results. According to Britten, L. at the School of Biomedical Sciences at the University of Leeds, Shire, K. at Institute of Psychology at the University of Leeds, Coats, R.O. at Institute of Psychology at the University of Leeds, and Astill, S.L. at the School of Biomedical Sciences at the University of Leeds, the standing desks have no adverse effects on performance and may even offer some benefit.

This result, although sort of unsatisfying, is very important. This result indicates that the design of ergonomic desks should include both a standing desk and a sitting desk with one possible ideal intersection between the two being a height-adjusting desk. Human Factors Engineers can design inclusively. When starting a design they must decide who is going to be included and who is going to be excluded. When designing a desk as adjustable engineers are able to include people with all preferences for height. This is a good solution because some people may want to always sit, always stand, or a mixture of both. Allowing for a height adjustable desk lets all these people use the product as they want.

Standing desks may currently be a fad with inconclusive data about their benefits but that does not mean that they are worth dismissing. They have no significant adverse health risks and therefore should be used by people that think they are useful. However, the best solution for whether or not to design a standing or sitting desk may be to design one that can be adjusted.



Article 1:

Benzo, R., Gremaud, A., Jerome, M., & Carr, L. (2016). Learning to Stand: The Acceptability and Feasibility of Introducing Standing Desks into College Classrooms. International Journal of Environmental Research and Public Health, 13(8), 1-11.


Article 2:

Britten, Shire, Coats, & Astill. (2016). The effect of standing desks on manual control in children and young adults. Gait & Posture, 48, 42-46.



Kelly, J. (2014, June 24). Proper Height Of Standing Desks [Proper Height Of Standing Desks]. Retrieved April 19, 2018, from https://notsitting.com/proper-height/

Ultimate Ears’ Great Design

Figure 1: Michel, B. Specifications of the UE Boom 2’s features [png]. Retrieved from https://www.ultimateears.com/en-us/wireless-speakers/boom-2.html

For the last two years I have been a proud owner of the UE Boom 1 and UE Boom 2 wireless speakers and could not be more happy. They are loud, portable, durable, and have good sound quality. Combined with great costumer service, these speakers are a really good purchase for anybody looking to buy a really robust portable speaker for parties or private listening.

In addition to being excellent speakers from an audio standpoint, they are also good speakers from a design standpoint.

From the moment of purchase the life of the product has been designed and thought through. The unboxing experience is incredible. All of the parts of the box really fit together nicely and provided tactile feedback while opening. It felt very much like a high-end product similar to opening an iPhone box. Here is a video of somebody unboxing the speaker:


As the video discussed briefly, the design of the buttons are very smart. They are very discoverable and the buttons have enough signifiers to indicate the role of the buttons. Additionally, the product is complex but its complexity does not impede its control. For example, the only buttons on the speaker itself are volume, power, and Bluetooth connect. These are the three essential functions of the speaker and therefore are the only controls on the speaker. According to my first article, the size of the buttons played a large impact on the effectiveness of the buttons in touchscreens. I believe that even though the speaker is not a touchscreen, the large size of the buttons aides in the use of said buttons. Additionally, according to the article, increased button spacing led to an increase in usability of the buttons. Both of these design elements are in use on the speaker. The speaker is sleek and simple which is a theme of the brand.

This theme is continued in the app design. The app designers added additional controls for the speaker all without making it more difficult to operate.

Here are some of screenshots from the UE Boom app:

Figure 2: Michel B. Screenshot of home page on UE Boom app [png]. Retrieved from UE Boom app.

This is the first thing that the user sees while opening the app. It makes sense that this is the first thing seen as it is the first step to using the speaker: turning the speaker on and connecting. From this screen the user can start to use all the other functionalities of the speaker such as connecting to multiple speakers or letting their friends connect to the speaker. A nice addition to the app is visible at the top. The white line above the words takes up about 1/3 the width of the screen and signifies which of the three swipe screens the user is currently looking at. This design element helps to orient the user.

Lastly, the app follows a good design convention of contrasting colors for clarity. According to my second article, using contrasting colors helps to communicate information. According to Sethumadhavan, A. (2016), “Present dark characters on light background versus light characters on dark background when designing displays. This is especially advantageous with smaller font sizes to facilitate better perception of details.” The app clearly does that by using a white font on a black background.

The UE Boom product suite follows excellent design principles and successfully makes a well designed and easy to use from an ergonomics standpoint product. I highly recommend the speaker to anybody that is exhausted with needlessly complicated portable speakers.




Tao, Yuan, Liu, & Qu. (2018). Effects of button design characteristics on performance and perceptions of touchscreen use. International Journal of Industrial Ergonomics, 64, 59-68.


Sethumadhavan, A. (2016). Five User Interface Design Tenets. Ergonomics in Design: The Quarterly of Human Factors Applications, 24(2), 31.


J. (2013, June 22). Retrieved April 10, 2018, from https://www.youtube.com/watch?v=fZBx8AWmWKs&ab_channel=JustinTse

Ultimate Ears BOOM 2 Portable Bluetooth Speaker. (n.d.). Retrieved April 10, 2018, from https://www.ultimateears.com/en-us/wireless-speakers/boom-2.html


Warning Labels

Figure 1. A warning label icon from http://www.safetysign.com/products/6287/general-warning-symbol-label

In America, it is possible to get sued for anything. The United States is known for its litigious culture and its products reflect that. Designers must design their products to advise and guide users away from unsafe operations as to prevent harm and lawsuits.

For this blog post I wanted to further investigate the ways that Human Factors Engineers increase product safety through the use of warning labels. To being, I found an article about the design elements that go into tools and systems for NASA. According to Yolanda (2009), “Design errors that occur in space projects essentially can be tracked to the difficult balance between the complexity of space systems and the relative ease by which failures…can propagate.” Yolanda continues to explain that in order to minimize risk, every single hazard that is present in the system must be fully understood and explored. Once they have been understood, then the system is safe to be operated. This guideline coincides with our class discussions of warning labels. When warning labels are made, they are created with very specific guidelines. They all start with either the word Danger, Warning, or Caution and are then followed by a statement to describe the hazard, the consequences of involvement with the hazard, and lastly instructions to avoid the hazard. These guidelines for warning labels could not be met if there was an incomplete understanding of the inherent dangers of a system. That is why Yolanda points to a complete and comprehensive understanding of the hazards to better create warnings for them.

My second article discusses possible issues with warning labels. The researchers conducted a study of workers using a certain piece of industrial equipment over a three month period which had warning labels and then asked them if they remembered what the labels said. According to McGarth (2011), “Results showed that equipment warning labels had a limited impact on workers.”

Figure 2. Locations of warning labels on table saw used in McGarth’s (2011) study. Notes. Illustrations by Rachael Anderson.

According to McGarth (2011), “If noticing a label is considered to have some beneficial impact, perhaps communicating a generalized message to use caution when operating the saw, then warning labels achieved at least a degree of effectiveness for the majority of the sample. However, if effectiveness is defined in terms of noticing, reading, and remembering what a warning label says, then warning labels were ineffective for the vast majority of workers.”

In my opinion, this lack of remembering suggests that warning labels are ineffective. In my opinion, they may be ineffective due to “alarm fatigue”. When there are so many labels and alarms then people are unable to internalize them and they become overwhelmed. This is what I think is happening with the warning labels. People expect them to be there and say obvious or irrelevant information so they tend to be ignored.

Regardless of the utility of warning labels, keeping users safe is an important and ongoing task for Human Factors Engineers. They must be willing to find ways to understand the risks involved in a system and constantly work to communicate safe operation to the users, even if that is not through the standardized warning labels.



Article 1:


Musgrave, Gary Eugene, Larsen, Axel M, Sgobba, Tommaso, & International Association for the Advancement of Space Safety. (2009). Safety design for space systems. Amsterdam ; Boston: Elsevier/Butterworth Heinemann.

Article 2:


Mcgrath, J. (2011). The Role of Equipment Warning Labels in the Industrial Workplace. International Journal of Occupational Safety and Ergonomics, 17(1), 49-60.

Design of Care Facilities


Recently, the design of hospitals and places to treat patients is becoming much more tailored to the actual needs of the patients. This increased focus has lead to some general guidelines and protocols for maximizing patient comfort which subsequently aides in treatment and improvements in patient health.

The first article I looked at discussed guidelines for creating care environments for people with Alzheimer’s disease because they have specific visuoperceptual considerations to design for. Due to the differences in the ways that people with Alzheimer’s process environments and the way that neurotypical people process environments, the care spaces require special consideration in their planning and design. A lot of the suggestions that the scientists mention involve placing constraints on the behavior of people with Alzheimer’s.

The need to improve these care spaces is huge because bad design choices lead to higher agitation among residents.

Here is a list of the negative design characteristics that should be improved:

  • Monotonous architectural styles and lack of reference points
  • Long corridors with many doors
  • Lack of windows and access to windows
  • Ad hoc signage

List of design elements that should be kept in mind while designing spaces for Alzheimer’s patients.

This article points to the need for designers to understand their users. When a designer understands the needs of the client they are able to tailor their designs to best meet the needs of the user to create a better product. The role of the designer is, according to Don Norman in his book The Design of Everyday Things, “To make things that satisfy people’s needs, in terms of function, in terms of being understandable and usable, and in terms of their ability to deliver emotional satisfaction, pride, and delight. In other words, the design must be thought of as a total experience” (293). And what is more of a total experience than the environment that an Alzheimer’s patient lives in? That is why it is so important to pay attention to what makes their living situation better.

Here is a graphic that shows some of the quirks that designers need to know about while creating environments for people with Alzheimer’s.


Perception quirks of people with Alzheimer’s

And here is a chart that explains some of the differences in Alzheimer’s patients vs. regular aging.

In my second article, I learned about another way that hospitals are being designed to become more patient-centered. Modern hospitals employ a similar concept as the Disney corporation in their amusement parks like Disneyland and Disneyworld. The main idea is that there is a front-facing area that makes up the world with the fantasy elements and behind that, concealed by walls, are the inner-workings of the park. This hidden area is where the machinery and support for the main park exists and takes place. According to the article, this design concept “structures numerous aspects of hospital design, from the layout of units to the positioning of the elevators, entrances and exits; and it structures policies about allowable activities and care processes.”

The goal of these changes is to create a more friendly and safe feeling space and to do away with the institutionalized feeling that hospitals tend to have. The hospitals also employed a concierge and added an emphasis on non-medical customer service.

These new protocols, changes in architecture, and emphasis on patient-centeredness increase the healing ability of hospitals by restructuring the way that people think of the space and its purpose. Typical hospital design focuses on treatment but does little in the way of treating patients and their families nicely. Modern hospital design attempts to change the way that people conceptualize the space by removing them from the medical treatment processes.



Article 1 – Alzheimer’s
Jones, G., & Van der Eerden, W. (2008). Designing care environments for persons with Alzheimer’s disease: Visuoperceptual considerations. Reviews in Clinical Gerontology, 18(1), 13-37. doi:10.1017/S0959259808002645


Article 2 – Hospitals

Bromley, E. (2012). Building patient-centeredness: Hospital design as an interpretive act. Social Science & Medicine, 75(6), 1057-1066.


Improving Health and Safety in Factories Without Compromising Productivity


Concept art of a futuristic factory control interface

In today’s market economy, the vast majority of the products we consume and interact with on a daily basis are made in large factories overseas. The purpose of these factories, both in size and location, is to reduce costs and therefore increase profit. However, large factories are presented with two large problems: worker safety and productivity maximization.

In my first article, I learned about a proposed way of increasing the usability of factory equipment using technology. This study researched three different ways of controlling equipment with a new interface. The three ways were time of flight (ToF), structured light, and stereo vision.

Stereo Vision

This method of observing inputs requires two cameras that are precisely aligned to capture images and 3D depth much like a human eye. The benefits of this system is that the cameras are cheap and can be customized to record a varying range of resolution that is best suited for the application. The drawbacks are that aligning the cameras is costly and that expensive processors are required to analyze the video input in real time.

Structured Light Systems

This method of observing inputs is seen in Microsoft’s Kinect. This system works by producing a disruptive light source and capturing many images to analyze. The benefits of this system are that the depth of the image is captured very precisely. The drawbacks are that it is not suited to very close up gestures and the alignment of the camera and light source are costly.  

Time of Flight

In this system, an infrared light is emitted and captured by a special sensor that translates the light into depth. This method has the benefits of being simple to process and ability to work at very close distances.

Understanding how these systems work is largely unnecessary but I thought it was interesting so I decided to include it. The goal of these three systems is to create a gesture-based interface rather than an interface that relies on physical controls because an operator will occasionally be required to operate several machines at one time. By allowing the operator to use gestures rather than operate physical controls, the operator can pay attention to the effects of what they are operating rather than the controls to operate it. The article discusses these benefits and largely suggests that it is the future of controls, however, I am not convinced.

In Don Norman’s The Design of Everyday Things, he discusses human error. I think that these gesture-based interfaces are much more prone to human error than their physical control based counterparts. This system would be prone to slips as it is possible that they will accidentally move their body too fast or in the wrong way to gesture to the controls the actions they wish to perform. Additionally, because the controls are not in front of the operator, they are likely to forget what the machine is doing and have memory-lapse slips. Lastly, this version of interface has no way to show the operator what mode the machine is in thus causing mode-error slips.

Workers at a large garment factory

Worker safety is another important topic in the design of factories from an ergonomics standpoint. This study tested low-cost and simple solutions to increase workers occupational health and safety in developing countries. According to the article they installed noise reducing covers, provided earplugs, added elevated platforms, slanted visual displays, and added extra exhaust fans. These changes to the factory cost less than $3000 USD but showed a marked increase in job satisfaction and workplace conditions.

Noisy workplace conditions can have far-reaching effects even outside of worker satisfaction. A noisy environment can cause a worker to have memory failures which can result in human error. Memory-lapse errors become common with added interference such as noise. Without any supplement help, the workers may experience enough interference from noise that their short-term memory (working memory) becomes overloaded and they forget to do part of the task. These memory-lapse errors can cause a loss of productivity or worse, injury or even death.

While searching for ways to increase productivity and lower costs, factory designers are looking towards alternative methods to accomplish these objectives. Sometimes the ideas in the design process are new and radical. These designs need to be considered thoughtfully and tested rigorously in order to make sure that they work and that they are safer for the factory workers. It’s important to remember that these factory workers are actual people that work in these factories for many hours and that their quality of life is important, too. It’s possible that improving their workplace conditions could improve their productivity, too. That is why the design of factories is important and should be done thoughtfully.

Article 1:


Harmon, Dan. (2014). 3D imaging systems bring advances to industrial automation: With an eye toward safety and ergonomics in factory automation, finding simpler and cost-effective ways to control factory floor equipment is of upmost concern.(TREND WATCH: SENSORS & MACHINE VISION: DESIGN APPLICATIONS)(dimensional). Design News, 69(2), T12.

Article 2:


Saw Bin, W., Richardson, S., & Yeow, P. (2010). An Ergonomics Study of a Semiconductors Factory in an IDC for Improvement in Occupational Health and Safety. International Journal of Occupational Safety and Ergonomics, 16(3), 345-356.

The problems with a TI-nspire cx with CAS.

I have always been frustrated with my TI-nspire calculator but until taking this engineering psychology class I did not have the proper vocabulary or knowledge to adequately express my frustrations with the design. This ‘rant’ may seem petty or oddly-timed considering it was for a calculator that I had to buy for high school math, but as I said, I have only now gained the proper knowledge to discuss my frustrations.

Ti-Nspire CX CAS Graphing calculator taken from Texas Instrument’s website. This is what the calculator looks like

The Buttons

My first issue with the calculator is the buttons. They have many issues but the first issue is that they are tiny. They are much smaller than the average hand would enjoy to press. It makes it complicated to both press the buttons as well as to read the labels on the buttons themselves. Their size forces the font to be small which further adds to the complications of using them. It is very easy to accidentally press another button entirely because the buttons are so close and so small.

My second issue with the buttons is that they are not enjoyable to press. They are shaped in stark contrast to earlier models of calculators made by the same company.

My friend’s calculator made by the same company with differently shaped buttons

If you look at the shape of the buttons on this calculator, you can see that they are concave inward to fit to the shape of a finger. That shape helps make the buttons discoverable as their purpose is to be pressed inwards. Additionally, the act of pressing the button is much more satisfying which makes the entire experience more pleasurable. Lastly, I’d like to point out that the buttons are much larger and much easier to read because the larger size allows for larger signifiers on the buttons.

The buttons have written out or iconic signifiers to help the user discern what each button accomplishes. These signifiers are often helpful when the symbols are recognizable such is the case with addition (+), subtraction (-), multiplication (x), or division (÷). It is much less helpful when the signifier just doesn’t make sense. On the TI-nspire there are many examples of unclear signifiers but I am going to call attention to the one that looks like “☐” . I may mean something to somebody that knows more about math than I do, but to me and my friends, it was puzzling. The signifiers do not work if they do not communicate a clear point to the user.

Another strange quirk of the button design is that Texas Instruments decided to use split buttons. I am not sure why they decided to use that design but I believe that it fell short in several ways. The first issue I have is that these split buttons are unsatisfying to press. I do not just mean that they could feel better to press, I mean that they are not always clear which side of the button registered if one side did at all. The second issue that I have with the buttons is that there is not always a consistent relationship between the operations that each side does. For example, on some of the split buttons there is multiplication and division, addition and subtraction, open parentheses and close parentheses, but on one there is ^ and x^2…okay…I guess that makes some sense. But on the one above that there is = and a menu for trig functions. Those two operations don’t have an easily identifiable relationship. I am not sure why those two functions were included on the same split button.

Hidden Functionality

Apart from the button layout as a whole, I have very specific problems with the buttons that the company did chose to include. Many of the commonly used functions are either hidden in further menus or require two button pushes to access. The process to access that secondary function of certain buttons is:

  1. The user must find the button that has the secondary function he or she wants
  2. Then find the button labeled ctrl (which TI was nice enough to color differently)
  3. Press ctrl
  4. Then press the original button to use the secondary function.

This design is inefficient. I understand why some functions require two presses. I understand what they were trying to do. My justification on Texas Instrument’s behalf is that the addition of more buttons would have meant that either the calculator would have needed to be bigger, or there would have been more buttons, or more things hidden in separate menus. Therefore, they decided to use secondary features for certain buttons. I understand that choice but in this case I think that they did not put enough thought into it. They chose to hide common functions behind other buttons thus making them inefficient to use despite how commonly they are used. For example, the square root function, ln, pi, e, and theta are all hidden as the secondary use of another button. That decision makes it tedious to use those buttons. There is a relationship between x^2 and the square root of x and that is why the square root is a secondary function of x^2 but because they are equally as important, it becomes tedious to have to press extra buttons to access that functionality. The decision has a reason but the costs vs. balances of that decision were not thought through. 

The Keyboard

My largest problem with the calculator, however, is the keyboard at the bottom. Taking up approximately one third of the button real-estate on the device, the manufacturer must have thought that users would be pressing the letters at least as frequently as the numbers or functions. From my personal experience both in high school and in college math, that scenario is not even close to the reality. The letters that I type are x,y,z,t,s, and g. I have not used all 26 letters in the same problem and I cannot figure out why TI thinks they all need to be accessible. I would have gladly given up the ability to type full essays on my calculator in exchange for larger buttons or a larger screen. However, I would like to point out that in the choice to include a full keyboard, TI did not include a regular QWERTY keyboard as is the standard for typing. No, they decided to go with an alphabetical keyboard instead with the space bar following the Z. There is nothing familiar to the user about the keyboard and it causes a lot of problems. Again, I have a possible explanation for why they chose to do that. My guess is that they realized that the most popular letters in mathematics are x,y, and z and the only way to make them easily accessible is to use an alphabetical keyboard because X, Y, and Z are at the end of the alphabet in sequential order. I think this claim is true because they even highlighted those three letters to make them stand out. However, this choice was short-sighted. By implementing such an unfamiliar layout, it makes it hard to find those letters anyway and slows the entire process down. They could have used a regular keyboard, highlighted those letters anyway, and also included them larger on other buttons closer to the actual numbers. Previous calculators have done without the dedicated keyboard so I am not sure why this one needed a dedicated keyboard.

However, according to this article, if Texas Instruments did decide that it was necessary to use a keyboard, neither the QWERTY nor the Dvorak keyboard would be the best choice, let alone the alphabetical keyboard that they did use. According to this article, a keyboard layout like this:

Keyboard II from article 1

is much faster and more efficient (fewer errors) than the other keyboards for typing when used with one hand as is often the use for both phones and keyboards. Therefore, if TI intended to include a functional keyboard on this calculator, one with this layout makes more sense for their intentions.

However, in a different study, it was found that an entirely different keyboard layout would be more suitable for mobile devices such as a PDA, phone, or calculator than the QWERTY or Dvorak keyboard and possibly even the one mentioned above. Here is the keyboard that was the best rated in measures like accuracy, time, and likability:

Keyboard that is best for mobile devices like a calculator.


It may be apparent that I wrote this post after doing seven hours of calculus homework and becoming increasingly frustrated with my calculator. I think that I am pretty harsh on TI for designing such an ergonomically inconsistent and frustrating calculator. However, I think that they make good tools they just don’t make them for their users. If they could design their calculators for the task or even for the human (or ideally both) then their users would be happier spending so much money on their products. TI only needs to make a few small changes to make a world of difference. It just adds up.


Calculator Picture:


Article 1:


Li, Chen, & Goonetilleke. (2006). A heuristic-based approach to optimize keyboard design for single-finger keying applications. International Journal of Industrial Ergonomics, 36(8), 695-704.

Article 2:


Hsiao, Wu, & Chen. (2014). Design and evaluation of small, linear QWERTY keyboards. Applied Ergonomics, 45(3), 655-662.


Ergonomics of Assembly Lines

I decided to investigate the ergonomic factors that impact assembly lines and their workers. With so much of our modern conveniences being created in large factories running large assembly lines, I wanted to learn more about the ergonomics issues facing these factories.

According to one article Lin (2001), “Quality continues to be a defining issue for both manufacturing and service industries… In striving for improved product quality, approaches have traditionally emphasized design of product and process to reduce variability” (p.377). Therefore, it is important to investigate any links between ergonomics and the ability to improve the quality of the products. Lin (2001) explains where the ergonomics issues come into play most importantly:

“Most line-based assembly tasks are paced, with a constant fixed time window available for task completion at each workstation. Any variability between workstations in the time required to perform the task will lead to some workstations being overloaded (i.e., insufficient time to complete the task) while others are underloaded (i.e., more time available than is required to complete the task). Line balancing techniques…are designed to reduce these imbalances, but perfect balance can never be obtained due to the differences between assembly tasks. Even with a well-balanced line, the cycle-to-cycle variability at each workstation means that on some cycles the operator will finish early and have to wait for parts to arrive, while on other cycles there will be insufficient time to complete the task…Incomplete cycles result in quality deficiencies because vital operations were not accomplished.” (p.378).
Basically, whenever there is any variability in the manufacturing process, quality will suffer. In comparison to assembly lines, other styles of organizing a manufacturing plant allowed for a “sense of ownership, autonomy, decision latitude, team culture, and nonpaced tasks” (p. 379) which resulted in a marked increase in total quality of the product without detracting from the productivity of the plant, according to Lin (2001). The increased control that a factory worker has in non-assembly line style manufacturing leads to an increased quality of the product with fewer defects. Making changes to the assembly line can provide workers with a greater sense of ownership and therefore increase the quality of their lives as well as the quality of the product.
The ergonomic challenges being assessed in this study were about how the amount of time each worker has to assemble a part or complete his or her task can effect the quality of the part and how does their posture (either good or bad) contribute to the quality of the part.
The study found that having incorrect (either too fast or slow) timing for the assembly line or having bad posture can show a decrease in quality. Therefore, the more ergonomically designed a factory is the more productivity it will experience.
I also investigated the role of assembly line workers on manufacturing lines. I learned a lot about how workers should behave and how their contributions are measured. In the second article Finnsgård, Wänström (2012), I learned about a new type of production method called ‘Lean Production’. According to  Finnsgård, Wänström (2012): “Lean production has in the last decades become the most important paradigm for production…In lean production, the focus is on the assembly operator, who should perform only value-adding work” (p. 2). Therefore, it is important to remove non-value adding work. The article discusses how assembly line workers should only be supplied with the materials needed to complete a task. Additionally, the parts of the task should be designed to best help the worker. Here are some of the design highlights:
1) The angle that a container used by a factory worker helps him or her complete the job better. Angled containers are better than their non-angled counterparts.
2) Horizontal containers do not seem to be the best choice because they create a weird situation with the worker’s center of gravity and the part’s center of gravity.
I was surprised at how detailed the guidelines are for helping design the work-spaces for assembly line workers. There are many factors that must be considered. A factory worker needs a lot of attention because anything short of optimization can result in worse quality of work and can slow down the entire assembly line.
Both articles show the importance of considering the worker when designing assembly lines. I think that it is really important to pay attention to the experience of the workers in the factory because they often go underappreciated despite all that they contribute. When workers go underappreciated the quality of their work goes down and the costs for the factory go up. There is no reason to not spend the extra effort to optimize their experience for better productivity and safety and efficiency.


Article 1: 

Lin, L., et al. “Ergonomics and Quality in Paced Assembly Lines.” Human Factors and Ergonomics in Manufacturing &Amp; Service Industries, vol. 11, no. 4, 2001, pp. 377–382.

Article 2:

Finnsgård, Christian, and Carl Wänström. “Factors Impacting Manual Picking on Assembly Lines: an Experiment in the Automotive Industry.” International Journal of Production Research, 2012, pp. 1–10.

Image Figure 1: 


Designing Safety Into Cars

I decided to investigate some of the potential implications for safety in the design of cars. I found two interesting articles describing different aspects of car safety. One article discussed the possible dangers of cruise control (LINK) and the other article discussed the potential for cars to go entirely mirror-less (LINK). These two design choices are going to be more and more important in today’s world of automation in transportation because with less need for the driver to be involved in the trivial tasks of driving, certain elements of the car can start to be removed as they become obsolete.


Image from Tesla.com explaining the improved safety that comes from their driver assist features.

Cruise control is a driver assistance feature in most of the cars on the road that helps a driver maintain his or her speed for long trips. This feature allows the driver to ignore the gas pedal and, in theory, focus on the rest of the road because there will be less need to modulate the speed of the vehicle. According to Markvollrath, Schleicher, & Gelau. (2011), the results of the study show that drivers were much less likely to drive above the speed limit than drivers that manually controlled the speed of their cars. However, there are some negative effects of both cruise control (CC) and adaptive cruise control (ACC).

With regular cruise control, drivers that wanted to slow down for a curve or fog were likely to do so about five seconds later than they would if there had been no cruise control engaged. According to the Markvollrath, Schleicher, & Gelau. (2011), “It seems that it takes some time for drivers to notice that a situation has arisen that the system is not able to handle and to intervene and override the system. The current study shows that this is not only the case for ACC but also for CC as well”.

Another interesting point brought up in the article by Markvollrath, Schleicher, & Gelau. (2011) is that “Drivers do not have to continuously watch and adjust the speed of the car since ACC or CC takes over the task of adjusting or maintaining speed. Drivers still have to watch the surrounding for traffic signs or road conditions that require the driver to adjust speed. However, it takes longer to intervene than when they drive manually. This may either be due to a reduced attention for signs or cues which require an adaptation of speed because this is taken over by ACC and CC. Or it may be due because of having to shift from automatic to manual control. Probably, both aspects are involved”. This finding was especially interesting because Tesla’s autopilot function requires that the driver take over in situations that the car does not know how to handle.

Is it possible that even with the possibility of necessary driver intervention that it could be more dangerous? If a driver is not expecting to take over is it possible that the mere act of taking over could be just as dangerous as having had control the entire time? The authors of the study suggest that due to peoples’ tendency to drive riskier because they are supported by the adaptive cruise control, the act of more automation to combat this tendency may actually be counter-productive. Therefore, “these driver assistance systems which take over only parts of the driving task may improve the well-being of the driver, but not traffic safety”, according to Markvollrath, Schleicher, & Gelau. (2011). This conclusion shows that the driver experience may be better in all aspects except in the case of an emergency. The user experience is better but that occurs at the expense of safety.

The second article I found was a discussion of the possibility of removing the mirrors from a car and replacing them with screens. They investigated this idea as a proof of concept to see if it could be safer or even possible. In addition to trying to improve the ergonomics, the study also noted that removing mirrors will reduce drag and increase efficiency. According to Bazilah (2014), about 90% of car driving is done as a visual experience. Therefore, if there are ways to improve the process of checking blindspots and surroundings to increase safety, that would be a much better design. Mirrors are already established to be a flawed design as Bazilah (2014) points out: “over 600 000 accidents occur in the United States when people are changing lanes. More than 200 people killed every year due to these accidents. 60% of the drivers who caused the accident say they didn’t see the other vehicle at the blind areas”.

This image is taken from the study published on the idea of mirror-less car technology.


The results of the study show that the use of the cameras completely removed the blindspots as well as the fact that the LCD displays were viewed as producing a much clearer image. The article discusses how the use of the LCD displays limits the driver’s need to move his or her neck thus reducing strain and becoming more ergonomic. The study concluded that their design using cameras rather than mirrors was superior in fuel economy, safety, and ergonomics.

I chose to discuss this article because it very successfully challenges our ideas about what makes a car work. People are used to the three-mirror system and changing to LCD’s may take some adjustments-time. Just because another system is superior doesn’t mean that it will be adopted. However, with the trend towards driver-less cars and full automation, it’s possible that there will need to be some middle-of-the-road solutions. In which case, a mirror-less car may help bridge the gap between fully manual driving and complete automation. The more changes that are made to the conceptual model of driving, the more people will be willing to accept the change from total control to much less control.


First Article (Cruise Control): Markvollrath, Susanne, et al. “The Influence of Cruise Control and Adaptive Cruise Control on Driving Behaviour – A Driving Simulator Study.” Accident Analysis And Prevention, vol. 43, no. 3, 2011, pp. 1134–1139.

Second Article (Mirror-less Cars): Bazilah, F. “Mirrorless Car: A Feasibility Study.” Applied Mechanics and Materials, vol. 663, no. Automotive Engineering and Mobility Research, 2014, pp. 649–654.

What is Human Factors?

Figure 1: furtwangen (Photographer). (2018). ENGINEERING PSYCHOLOGY – MAKING TECHNOLOGY HUMAN [Digital Image]. Retrieved from https://en.hs-furtwangen.de/faculty/industrial-technologies/engineering-psychology.html

When humans are involved, the design process becomes much more complicated. Humans require the use of many specialized design principles because of the nature of humans. That is where the field of Engineering psychology/ergonomics/human factors comes in. However, those names are confusing. Here is an overview of what those fields are and why they are important.

Engineering psychology/ ergonomics/ human factors engineering are all closely related and often really confusing to distinguish. When used to its best potential, ergonomics helps provide a fluid experience while optimizing well-being and performance. When not used correctly, human well-being, safety, and efficiency can suffer.

The definition or ergonomics according to the International Ergonomics Association is: “the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and other methods to design in order to optimize human well-being and overall system performance.”

Human factors and ergonomics focus on the human-side of design to optimize how human traits work with technology. Humans interact physically, cognitively, and behaviorally with technology which makes it an important field to take part in. Due to the increasing prevalence of technology in everyday life, understanding how to make products and processes better for people is more important than ever before.

Just think, in your day to day life, how often have you struggled to do a seemingly simple task? You may be inclined to blame yourself observes Don Norman, author of The Design of Everyday Things, when in reality, it is the designer who failed you. For example, watch this video by Vox (2016) to better understand how designers have failed you in the simple task of opening a door.

According to Norman, when some product is poorly designed and people “fail to follow these bizarre, secret rules, and the machine does the wrong thing, its operators are blamed for not understanding the machine, for not following its rigid specifications. With everyday objects, the result is frustration. With complex devices and commercial and industrial processes, the resulting difficulties can lead to accidents, injuries, and even deaths” Norman, D. A. (1988) Book. New York, New York: Basic Books.

Bad design because it lacks discoverability and takes too long to find the correct button.
Source: https://www.demilked.com/one-job-poor-design-decisions-fails/

Engineering psychology is about making things better for people to use. This goal can manifest itself in many ways but the most obvious are safety and efficiency. With proper design being implemented with technology, people can be safer and more productive. By studying interactions between humans and the products we design, we can attain a safer, and more productive harmony.






International Ergonomics Association


Norman, D. A. (1988) Book. New York, New York: Basic Books.

V. (2016, February 26). Retrieved April 12, 2018, from https://www.youtube.com/watch?v=yY96hTb8WgIImages:

Furtwangen (Photographer). (2018). ENGINEERING PSYCHOLOGY – MAKING TECHNOLOGY HUMAN [Digital Image]. Retrieved from https://en.hs-furtwangen.de/faculty/industrial-technologies/engineering-psychology.html

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