Usability Evaluation on Tesla Model 3 DashBoard
Tesla launched their most affordable electric car to market, the Model 3, in 2017. The vehicle is distinctive in its simple internal controls, consisting of a single centralized touchscreen and steering wheel instrumentation. With this blog article, I am going to do a comprehensive usability evaluation on Tesla Model S Dashboard. First of all, let me explain the general idea of usability engineering.
Usability engineering is an essential and important professional discipline that aims to improve the usability of interactive systems. To describe problems that arise during the use of such a device, it draws on theories from computer science and psychology. Usability engineering involves concept checking, with users or with usability experts, at different stages of the development process. In this sense, the history of usability engineering goes all the way back to the ’80s. In 1988, authors John Whiteside and John Bennett of Digital Equipment Corporation and IBM written content on the topic, isolating as key activities the early setting of goals, iterative evaluation, and prototyping. A pioneer in the area of usability engineering is the usability expert Jakob Nielsen. In 1993 Nielsen outlines approaches to be used in a product development process in his book Usability Engineering, so designers can ensure that easy to learn, efficient to use, easy to remember, few errors, subjectively pleasing (Nielsen, 1993)before the product is introduced are considered. The work by Nielsen explains how to execute usability tests and how to use usability heuristics in the lifecycle of usability engineering. Through this method, ensuring good usability avoids problems with product adoption after launch.
Instead of concentrating on seeking solutions to usability issues, which is the focus of a UX or interaction designer, a usability engineer focuses mostly on the research phase. It is not solely a design job in this sense, and because of this, many usability engineers have a background in computer science. Moreover, its relation to the design aspect is also vital and not least, because it provides the fundamental mechanism within which designers can function to ensure that their products are properly connected to their target customers.
That is the basic introduction for usability engineering, let me come back to our specific topic “Tesla Model 3”.
The Tesla Model 3 was the best-selling luxury car of 2018, according to the Capparella 2019. The Model 3 is a direct indicator of how businesses have started to integrate and move away from conventional in-vehicle interfaces with self-driving features. For the control of almost all primary and minor features of the vehicle, the Model 3 is fitted with a single 15-inch touchscreen. This is a fairly dramatic change in the manner in which drivers view and obtain information, removing dashboard complexity and any manual buttons or knobs as elements of the infotainment system.
Compared to the wider problem of system acceptability, usability is to some degree a narrow concern, which is simply the question of whether the system is good enough to fulfill all the needs and aspirations of users and other potential stakeholders, such as consumers and managers of users. Moreover, the overall acceptability of a computer system is a mixture of its social acceptability and its practical acceptability.
Social acceptance, referring to a cultural phenomenon, may be defined as a wider term, whereas social acceptability is usually used to refer to a design with the quality attribute of being socially acceptable. This separation, however, is hardly established; in fact, both words are used to refer to how the user receives an interface use, both internally and externally, from others. A lack of social acceptability can make an interface, program, or technology practically unsuccessful. At the same time, access to specific software, programs, or information can be forbidden by a user who refrains from using an interface that adheres to a social context. As a result, this preferred non-use of technology could reduce service accessibility, as well as obstruct social empowerment and social equity. (Marion Koelle, 2019 ). Most of the time the systems ask some detailed privacy relates questions from the user to verify that those are the real intended users for the system. In that way, most of the time the systems lose the system’s social acceptability. So, the system designers should carefully think about those trade-offs while designing the system .when we consider the tesla model 3 dashboard in this aspect, the social acceptability is very high among most people. The reason behind that is normally tesla do not ask(do not need) privacy-related question from the users. So, the social acceptability level can be mention as very high.
As I mentioned previously, to fulfill the overall acceptability of a computer system the next factor is practical acceptability. It consists of many aspects one aspect is traditional categories. Traditional categories such as cost, support, reliability, compatibility with existing systems, etc. now let me talk about those factors with the tesla model 3.
Here the cost factor does not apply to this scenario since the user has to pay for the car itself. no separate cost for the screen. But some might be argued that the facilities provided by the screen are not enough for an expensive car like that. When we talk about the support factor, it provided manuals in several places while navigating the screen. However, they do not provide search functions within the manual or with the screen. That is the main drawback. There are not any big issues reported with the reliability of this system. but when we talk about the compatibility of the tesla model 3 screen the main issue is it won’t support Neither Apple CarPlay nor Android Auto is available on the Tesla Model 3. It does, however, deliver a lot more than what those two platforms actually do for phone integration. For example, if you like to sing, you can make use of the karaoke function of the car, in which you can sing along with the lyrics shown right on the screen to your favorite songs. Furthermore, you can stream Netflix and watch YouTube videos, which are activities you cannot do with Apple CarPlay. (Santos, 2020).
I was talking about the traditional categories of practical acceptability. The next aspect is usefulness .the basic idea is whether the system can be used to achieve some desired goals. Tesla Model 3 is provided the ability to achieve almost all the desired goals with many cool features. The subcategories of usefulness are utility and usability. Where utility is the matter of whether the functionality of the system can do what is expected in principle, and how well users can always use the functionality is the question of usability. (Nielsen, 1993). When we look at the tesla modal 3 screens in the utility aspect, it is very successful because fundamentally it’s an infotainment system that provides both entertainment and information about the built-in system(the car). The tesla modal 3 screens provide both of those aspects very well.
It is necessary to note that usability is not a single, one-dimensional property. Usability has several components and· these five usability attributes are generally correlated with it.
Learnability: It should be easy to learn the system so that the user can start getting some work done with the system quickly. Tesla offers a brief training session for new users in person. Via shortcut information buttons and an accessible car manual, the device itself also offers some assistance to beginner users but is much more suited to seasoned users.it will increase the learnability of the overall system. apart from that that they use some common symbols to represent the functionalities. To get a comprehensive idea about learnability we can look at the learning curve. (Nielsen, Usability Engineering, 1993).
Efficiency: The system should be efficient to use so that a high degree of productivity is possible once the consumer has learned about the system. Tesla Model 3 provide some shortcuts to the expert users to increase the efficiency
Memorability: The system should be easy to remember so that after some time of not having used it, the casual user will return to the system without having to learn it all over again. as I described later in this discussion, in this tesla model 3 interface most of the icons are familiar to any user. They used similar icons that are familiar to most of the users. so the memory load is minimized.
Errors: The application should have a minimum error so that users make few errors during system use and can quickly recover from them if they make mistakes. Additionally, disastrous mistakes do not happen.
Satisfaction: The device should be fun to use so that by using it, users are subjectively satisfied; they like it. The tesla model 3 interface provides many cool features to increase the user satisfaction of it. By simply providing a questionnaire to the real and we easily measure this aspect of the Tesla Model 3 screen.
All of these aspects related to the Tesla Model 3 display will be discussed in detail in the following sections.
All of these aspects related to the Tesla Model 3 display will be discussed in detail in the following sections.
Next, I am going to discuss the ten heuristics that aid evaluators in discovering usability problems under the heuristic evaluation. The fundamental goal of usability testing is to produce products and services which are highly usable. That is an uncontroversial declaration. The way different approaches to usability testing have different ways of achieving the purpose is where things can get a little complicated. We can identify general goals of usability as (Lewis, 2020),
Goal 1: To Discover Problems
In diagnostic problem discovery studies, the primary task is the discovery, prioritization, and resolution of usability issues. This is the most popular goal of testing and perhaps what most practitioners (and the general community of product development) have in mind when talking about usability testing.
Goal 2: To Compare Against a Benchmark
Standard reference points that make measurements more meaningful are benchmarks. They are used in many areas, including usability testing. with the experience, though many researchers use metrics, many do not generally compare their use of metrics to one or more benchmarks in their usability studies. for our Tesla Model 3 example, we can establish a benchmark as the time taken to turn on the headlight via the dashboard interface.
Goal 3: To Compare Against Another Interface
Another form of measurement test (and the third objective) is to carry out usability tests to explicitly compare two or more interfaces. For our example, we can test the tesla model 3 interface with the tesla model x interface. And also we do this another manufacture’s product as well. For example, we test the tesla model 3 interface with Volo xc 90 autopilot infotainment system
1. Simple and Natural Dialogue
User interfaces should be clarified as much as possible, because one more thing to remember, one more thing to probably misunderstand, and one more thing to search for while looking for the thing you want is an additional function or item of information on a computer. In addition, interfaces should match the function of the users as naturally as possible, so that the mapping between machine constructs and user concepts becomes as easy as possible and minimizes the navigation of the users through the interface.
There are few things on the Model 3 panel which do not follow the traditional mapping from user input to screen output. Both mistakes are very minor and can totally avoid user notification. The first is the incongruence of controls on volume. By pressing up or down, the left button on the steering wheel will raise or lower the volume. The on-screen volume bar indicator, however, is horizontal, indicating a rise in volume to the right and a decrease to the left. The alternative is simply to change the volume display into a vertical scale volume bar to fit user input on the wheel.
The second issue found is the turn signals, which are shown blinking on the screen to the right of the driver when triggered, whether the driver is turning left or right. Adding left and right blinker indicators to the dashboard behind the steering wheel will fix this incongruity.
1.1 Graphic Design and Color
In achieving a clear and natural dialogue for modern computer systems with graphical user interfaces, good graphic design is an essential factor. There are some basic factors that can lead to smoother dialogues, in addition to getting guidance from a graphics designer.
With the interface of the tesla model 3 interface, we can clearly identify the separations of distinct areas of functions. In the below picture I have highlighted those sections with red squares. and also with this image, we can see the speed displayed with highlighted colors. That is because the speed is very critical and important information for the users.
Another main consideration of this is color usage. In this model 3 display they did not overuse color, only limited to few color variations. And most of the time the designers of the tesla model 3 screen have used colors to categorize differentiate and highlight some special things like high-speed situations and warnings, current location.
But by looking at this display we can see a lot of information. With that, there is a risk of confusing novice users as well as slow down the expert users. That is a bad aspect of this approach.
Once the pedestrian crossroad accidentally, the screen gives the warning with blinking lights since this is an extreme case. The screen tries to get the full attention of the driver by providing some beeping sounds as well. This example can be identified as an important usage of the principle of graphic design to help user prioritize their attention to a screen.
2. Speaks the user’s language.
As part of a user-centered design, user interface terms should be focused on the language of the users and not on system-oriented words. With the given example image, we can identify how the tesla introduced the details of the car. They use the heading “About your tesla” instead of “About the vehicle”. This is a very good example of they try their maximum effort to express the information in a user-centered approach instead of a system-oriented way.
There are a lot of examples for mapping between the computer display of information and the user’s conceptual model of the information. Almost all the icons on this screen represent the usage of it.
3. Minimize user memory load.
Computers are good at very accurately recalling items, so they can take over the memory burden as much as possible from the user. In general, people have a much better time than trying to retrieve the same details from memory without assistance in remembering something that is presented to them. In carrying out vehicle tasks, users should be able to rely on recognition as opposed to memory. The absence of labels on the steering wheel buttons is one problem that emerges with this heuristic. Although physical labels are not recommended as button functions shift, it will restrict the number of options kept in user memory at any given time to note the current role of the buttons on the screen.
And also, as I described earlier, in this screen most of the icons are familiar to any user. They used similar icons that are familiar to most of the users. so the memory load is minimized.
for example, anyone knows the hand lens symbol is for search option, signal mark for the amount of signal has, padlock symbol for implying that its locked, western music symbol for music, etc. . Other symbols also represent their own inherited meanings.
4. Consistency
One of the most fundamental concepts of usability is consistency. If users understand that the same order or the same action will still have the same impact, they will feel more secure in using the system and will be motivated to try exploratory learning techniques because they will already have part of the information required to operate new parts of the system.
There have been some problems where the interface and controls either lack consistency in the interface or do not comply with industry standards in a way that raises the likelihood of errors. First, on all displays, even when viewing the car manual, the escape ‘x’ at the top left corner is the norm. In that case, with no such indicator given, the user must swipe down to exit. The choices for exits should be consistent throughout.
The involvement of cruise control in the current settings is counter-intuitive. To put the car into drive or neutral, the right-hand stalk must be shifted upward. The consumer moves the same stalk downwards to engage the cruise control, going past the ‘drive’ and ‘neutral’ settings. This goes against the driving principles of an automatic vehicle, which, when the vehicle is in motion, usually does not require gearshift movement. The addition of a distinct control choice, whether in the form of an additional lower right stalk or a button on the wheel, could be a possible solution. (Eva L. Parkhurst1, 2019).
5. Feedback
The device should notify the user constantly about what it is doing and how the user’s input is perceived. Feedback should not wait until an error is encountered: constructive feedback should also be given by the system, and partial feedback should be provided when information becomes available. Users should be notified of the status of the system and receive suitable and timely feedback. Although the screen shows the present system condition clearly, during more hazardous driving conditions, the driver may not receive this information as necessary, particularly as more complex screens can draw more visual attention off the road. For example, while on the top left of the screen the current vehicle speed is visible, more timely input may be given from behind the wheel location, within the road line of sight.
Another valuable feedback is the low battery feedback provided by the Tesla screen
Another two kinds of feedbacks; parking brake off and vehicle power off is shown as follows.
6. Clearly Marked Exits
Users do not want to feel like they are stuck within the system. The program can give the user a simple way out of as many problems as possible in order to improve the user’s feeling of being in charge of the conversation. For instance, to bring the user back to the previous state, all dialog boxes and system states should have a cancel button or another escape facility.
The Tesla screen offers different ways to exit from erroneously selected screens, but not all choices are evident to users. As I discussed earlier a tiny ‘x’ on the top left corner of the screen is the most visible, which can be hard to click when the vehicle is in motion. Although no such indication is given, users may alternatively press or swipe down outside the dialog box. It could help users learn about such features by offering a “training” or “new user” mode.
7.Shortcuts
For the novice and expert users, the device should be adaptable. Tesla offers a brief training session for new users in person. Via shortcut information buttons and an accessible car manual, the device itself also offers some assistance to beginner users but is much more suited to expert users. The inclusion of a “new user” mode, which could include tips to help users understand the system and some of the secret features or shortcuts, could significantly help users get comfortable with the system interface and get the most out of it, as previously described.
One shortcut is to change the volume of the music player the user only needs to swipe the music icon, instead of the press that button and change the volume with the horizontal scale.
Another shortcut is by long pressing the fan icon the user can turn on the A/C.
8. Good Error messages
For two reasons, error situations are important in usability: First, they reflect situations where the user is in difficulty to be unable to use the device to accomplish the desired target. Second, they provide ways to help the user better understand the system because the user is typically encouraged to pay some attention to the content of error messages and because the machine already has some understanding of what the issue is. (Nielsen, 1993)
Users should know when a fault occurs and offer recovery assistance. With voice commands, a glaring issue with the Tesla interface indicates the error. If the device does not process a request, users are provided with no input, as the screen simply reverts to the previous view. Adding a message that tells the user that the device either does not understand the command or is unable to execute the operation will suggest that the system has attempted to process the command. It will also improve the usefulness of this feature by adding a shortcut to the vehicle manual or information that shows legitimate command options.
The below figure shows the “Car needs service ” message.
When we consider the error messages of tesla model 3 those messages are in clear language and don’t use complicated codes. But some of those error messages are not very precise for example in the previous example mentions that the car cannot charge and needs service. It should be more precise than that. And it should provide some more information (other than doing servicing)to solve the problem as well. But there is a good aspect that is the system does not blame the user for those errors. Just mention the current erroneous condition.
9. Prevent errors.
The tesla designer should carefully think about it to prevent errors from occurring. There are several quick-press buttons at the bottom of the GUI panel in Model 3.those buttons are very close to each other and some contribute to menus, while others cause an immediate change. Selecting the seat icon, for instance, triggers seat heaters, while clicking the car icon leads to the main menu. A distinction between the button functions would be provided by adding a simple menu indicator next to the relevant icons.
10. Help and documentation
As I describe earlier any usable system should have a proper way to provide accessible help and documentation. This model 3 screen also, provides manuals in several places while navigating the screen. But the main drawback is currently they do not provide a search function within the manual. As a solution for this usability issue, we can suggest adding an onscreen search function of a voice-over search function to the system.
Another aspect we need to discuss here is in tesla they do update the software periodically with the permission of the user. And they show the new and changed features to the user. But the users reluctant to read carefully these details because at that time their main intention is to travel somewhere, so my suggestion is to send those details of the update via email or any other media.
formative evaluation and summative evaluation.
The purpose of the test should be explained before any testing is carried out, as it will have a direct effect on the type of testing to be performed. Whether the evaluation is meant as a formative or summative assessment of the user interface is a significant distinction. Formative assessment is performed as part of an iterative design process to further refine the interface. Thus, the main objective of formative evaluation is to learn which detailed characteristics of the interface are good and bad, and how to improve the design. A thinking-aloud test is a common approach to use for formative assessment. It is a Simple usability test where users think out loud are cheap, robust, flexible, and easy to learn. Thinking aloud should be the first tool in your UX toolbox, even though it entails some risks and does not solve all problems (Nielsen, thinking-aloud-the-1-usability-tool/, 2012).
This approach can be effectively used for tesla model 3 screen evaluation as well. Summative assessment, on the other hand, attempts to measure the overall quality of an interface. For example, to appreciate how important the competition really is when choosing between two alternatives or as part of competitive analysis. For this, we can select the Volvo xc90 autopilot infotainment system and we can perform the Summative assessment .A common approach to be used for summative assessment is a measurement test.
When we talk about finding employment test users in usability with the simulated testing there are main two ways . the main type is to find users for a system that is targeted to a certain type of users. Hereby in our case, this might be effective since we need to test the tesla model 3 dashboard which is designed and targeted for certain types of users., Those users can be more or less diverse. And also, those users can be found out from different locations. Sometimes the existing users like to join to do these usability tests. Because they can feel the upcoming features prior to the others. It will be a more cost-effective and successful approach for the testing team as well. For example, we can find current tesla users to do this evaluation/test. In this approach we I state several ways of finding test users one is recruited from temporary agency which are specialized to provide employees for these kinds of user interface tests. And also, we can find domain interest people from universities or any other colleges. Furthermore, we can find employees via classified advertisements ,who are currently work in another place. Here it is essential to pay salary them.
There are two major categories among those test users. Those are novice users and expert users. Almost all the user interfaces need to be tested with novice users. And also, many systems should be tested with expert users as well. Typically, these two groups should be tested in separate tests with some of the same and some different test tasks. (Nielsen, Usability Engineering, 1993)
Next, I’m going to describe about the Compare and contrast two ways of employment test users in usability testing with this simulated testing. Those two ways are.
· Between-subject
· Within-subject
In some sense, between subject testing is the easiest and most valid since it requires using different test users for the various systems. Each test user, therefore, participates only in a single test session. The huge individual difference in user skills is the issue with between-subject designs. For example, we can use different test users to test usability of the lighting functionalities the tesla mode 3 interface. And another uses to test usability of the air condition functionalities the tesla mode 3 interface. In order to smooth over random differences between test users in each of the classes, it would be appropriate to run a very large number of test users in each condition. But in that way, it might be very costly.
The next type of employment test users in usability testing with this simulated testing is Within-subject testing. In this approach all the test users get all functionalities to be testes .here we do not divide test users only for a particular aspect of test as we discussed in the previous type.so the individual variability can be control as much as possible. But with this approach the problem is by doing the initial set of tests the novice users become expert users and the intended aspect cannot test properly. For example, let us say we want to test lighting functionalities first and second the air condition functionalities. The problem is most of the time for the first task the users take much high amount of time and with the exposure they learn the system. Because of that for the second task (usability of A/C test) they take less amount of time. The record reflects that the second task is much more usable than the previous test(lightning test). But it is not the truth.
The investigator should ensure that the test room is ready for the test, that the computer system is in the starting state specified in the test plan, and that all test materials, instructions and questionnaires are available in preparation for the experiment. All files used for test tasks, for example, should be restored to their original content and any files generated during previous tests should be transferred to another device or at least another directory.
Stages of a Test
There are 4 stages in usability tests.
1. Preparation
2. Introduction
3. The test itself
4. Debriefing
The first step is the preparation stage. The experimenter should ensure that all the testing equipment’s are ready for the test, that the computer system is in the starting state specified in the test plan, and that all test materials should be available. in our case we need to prepare fully functioning tesla dashboard the test . All files used for test tasks, for example, should be restored to their original content and any files generated during previous tests should be transferred to another device or at least another directory.
The next stage is introduction stage. The first thing to do in this stage is to introduce the test to the test users and to give brief explanation, purpose of the test. For an example, the experimenter can give some brief introduction about that they want to test the usability aspects lighting functionalities of tesla model 3 bash board. There are major components should cover in test introduction. Experimenter should explain that the purpose is to test the tesla model 3 dashboard, and not the user. Or else the user might set stressed while doing the test and the test results might get change. Also, the test results should be used to improve the user interface of the tesla model 3 dashboard. Ask them that the system is confidential and that others should not be known about the test . It may also be a good idea to encourage the test user to refrain from sharing it with colleagues who may be involved in future experiments (even though the method is not confidential) so as not to bias them. And also, the experimenter should give the opportunity to the test users ask question about the test. And also, the physical setup should be well suited for individual user. For our example prior to do the test the seat position and the steering wheel position of the tesla car should be adjust with the individual user. Another the thing is to provide the instructions inwrite to the test users.
Next stage is the running test stage. The experimenter should not provide any interactions to the test users. Some time people tend make some unintended noises to while looking at some tasks . those sounds can be act as hint to the test users so the test experimenter should avoid making even a less amount of noise while conducting the test.
The last stage is the debriefing stage. Where the user is debriefed after the test and is asked to fill in some questionnaires about subjective satisfaction. In order to eliminate any bias from the experimenter’s statements, questionnaires should be implemented before any other system discussion.
In this blog article, we have discussed the usability evaluation of the Tesla Model 3 dashboard in many usability concepts. With the deep description, I hope you all got a clear and comprehensive idea about the usability aspects related to the Tesla Model 3 dashboard. Thank you.
References
Eva L. Parkhurst1, L. B. (2019). HEURISTIC EVALUATION OF A TESLA MODEL 3 INTERFACE. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 1515–1520.
Lewis, J. (2020, 2 11). Retrieved from measuring: https://measuringu.com/three-goals/
Marion Koelle,. T. (2019 ). What is (Un)Acceptable? — Thoughts on Social Acceptability in. Interactions-https://doi.org/10.1145/3319073, vol 26(3), 36–40.
Nielsen, J. (1993). Usability Engineering. Academic Press.
Nielsen, J. (2012, January 15). thinking-aloud-the-1-usability-tool/. Retrieved from Nielsen Norman Group: https://www.nngroup.com/articles/thinking-aloud-the-1-usability-tool/
Santos, J. (2020, December 16). Does the Tesla Model 3 Have Apple CarPlay? Retrieved from motorbiscuit: https://www.motorbiscuit.com/does-the-tesla-model-3-have-apple-carplay/