team execution pass 2 report: bmw x5’s digital...

University of British Columbia

EECE 418 – Human Computer Interaction Group #: 4

Team Execution Pass 2 Report:

BMW X5’s Digital Dashboard

Sam Mohamad-Khany – 42728022 Sukhdeep Brar - 57775029

Aaron Cop – 45354024 Imraj Pasricha -79558011

Design Rationale for the Digital Dashboard System

In Pass 1 of our EECE 418 project we outlined the concept for the Digital

Dashboard in car media and navigation system. The impetus to design the Digital

Dashboard came from a desire to improve the complex and unfriendly user-interface of

the BMW X5’s current navigation system. We used a myriad of prototyping and

evaluation techniques to iteratively develop the Digital Dashboard in a user focused

manner. We are now at a stage where we have a framework of the system which we will

translate into a higher fidelity prototype and carry out real user tests on.

Initially when investigating the BMW X5’s navigation system we were mostly

concerned with improving the impractical method of inputting data, which was using

turn-and-push knobs. As we delved deeper into system we discovered that the

multilayered menu system was perhaps an even bigger obstacle to usability. The user

had to remember an interrelated hierarchy amongst the different menus and modes of

operation and also the rules and steps to traverse between them. The ultimate goals of the

Digital Dashboard, consequently, became the elimination of modes and complex menus

and also the integration of an intuitive and easy input method. We believe we addressed

these two issues well with in our Pass 1 prototype. Throughout the course of heuristic

and cognitive walkthrough evaluations many valuable issues and problems were

identified with our initial design and we incorporated these into a second low-fidelity

prototype. The fundamentals of our design, however, appear to be sound and our concept

was well received in our preliminary evaluations. The higher fidelity prototype

developed for Pass 2 will largely be based on the second iteration of our low-fidelity

prototype.

The two critical question for which we need to carry out a quantitative analysis in

order to authoritatively answer are:

Is the Digital Dashboard easier/faster to operate than the BMW X5 for

media and navigation tasks?

Is the Digital Dashboard easier/faster to learn and understand than the

BMW X5’s navigation system?

Can the Digital Dashboard be safely operated while driving?

Since an in-vehicle navigation and media system is considered a luxury item it should

provide utility and be inviting for the user and not be a chore to operate. Since BMW and

other automobile manufacturers already charge upwards of three thousand dollars for a

navigation system, it should proffer significant value to the customers. Navigation

systems are also a large selling point for higher class automobiles and a unique and

innovative system, such as the Digital Dashboard, could be very marketable to potential

customers.

In order to test the differences between the Digital Dashboard and the BMW X5,

answer the questions posed above, and ultimately sell the idea of the Digital Dashboard,

various qualitatively and quantitatively methods will have to be employed. Our focus in

these evaluations will be the overall look and feel of the system, and ease of interactivity

supported by the touch screen-interface. To achieve this we will focus more on

implementing the media portion of the Digital Dashboard, which having a mostly

superficial implementation of the navigation system.

PROPOSED DESIGN

After careful analysis, we have decided to implement following functionality to

demonstrate the feasibility of our system. The philosophy adopted by the team behind

this decision was that the prototype should provide enough functionality for the test user

to get a proper feel and grip of the system. Once accustomed with the prototype, the user

would have little difficult in making the jump to the full system.

I) Main Menu

The main menu will include links to the other sub-menus. Links would be

look like smaller thumb-nails of the sub-menus. Expert users will be able to

use the functionality of the sub-menus from the main menu. In the beginning

we expect our users to use the sub-menus.

II) Volume

The screenshot below shows the volume sub-menu. User can increase and

decrease the volume. The “x” button at the top takes the user out of this menu

and to the main menu.

III) Radio

The screenshot below shows the radio sub-menu. It allows the user to change

the radio station, select their favorite radio stations, program their favorite

radio stations. The “x” button at the top takes the user out of this menu and to

the main menu.

IV) Tracks

The screenshot below shows the tracks sub-menu. It allows the user to select

and play the tracks. The “x” button at the top takes the user out of this menu

and to the main menu.

V) Limited Navigation System

We have decided not to implement the navigation system in entirety due to the

increased complexity and time constraint for the project. We will however,

implement a limited navigation system without keyboard support. This will

demonstrate the effectiveness of the menu system without the actual

implementation of the functionality.

A2: Additional Analysis and Evaluation

After our initial heuristic analysis and cognitive walkthrough, we used this new

information to perform a redesign of the Digital Dashboard system. One of the troubled

areas which we identified was that of exiting the different submenus back to the top-level

menu. There was no mechanism which would take the user back to the top-level menu

except for waiting for the menu to time-out. We realized that this many confuse novice

users or put them under a perceived time pressure to carry out their intended functions.

For expert users, the extra seconds of wait time to perform the next task may also lead to

frustration. Thus, it was decided that a close icon would be added to each screen and the

time-out would be extended to accommodate novice users.

This is one example of multiple improvements which were made to the Digital

Dashboard in the second iteration of low-fidelity prototype. The second iteration is

documented in our Pass 1 portfolio. We also entertained the ideas of improving the data

input method for the navigation system with the keyboard. In the end we decided to stay

with our current design as the navigation system can be a whole project in and of itself.

A3: Prototype Redesign

After much consideration and experimentation we decided that Macromedia Flash

would be the most appropriate prototyping tool. Flash allows us to utilize advanced

animation technique and also provides scripting capabilities. Currently, the overall menu

system and look and feel are represented by the Prototype. The multimedia interface

components are almost completely implemented and this allows us to carry out our

comparisons and measurements against the BMW X5’s navigation system. However, the

buttons don’t trigger the actual functionality. For instance, pressing play will highlight

the play icon, but will not result in music actually playing. The following are screens of

our current working prototype:

Initial Off Screen

Figure 1: This screen shows the state of the Digital Dashboard before it is physically

turned on. The green button represents a real power button, or switch.

Top-Level Menu Screen

Figure 2: This is the main screen of the Digital Dashboard through which all of the other

functions are accessed. By touching different “hot spots” on the screen, various sub-

menus open.

Track Selection List

Figure 3: The track selection list is shown in these pictures. By clicking different tracks,

the track gets selected.

CD Playback Screen

Figure 4: The CD controls are accessed from this screen. Touching the different icons

will result in a different action.

Volume Control Screen

Figure 5: On the volume screen, moving one’s finger across the volume selector will

change the volume and the graphics will also change to reflect this.

Highlighted Info and Options Screen

Figure: When one presses a “hot spot” it is highlighted before it pops up, as shown with

the Info and Options.

Section B: User Evaluation Plan

Representative Users

The representative list of users for the Digital Dashboard will be similar to the one

outlined in Pass 1 of the project. We will attempt to find real users that fall roughly in

line with the following traits:

An educated Professional: These users are mostly likely bright individuals who

expect their automobiles to be sleek and sophisticated. Though they may not

necessarily be technology or computer literate, they should easily be able to figure

out an in-car computer with a good interface.

A Techno-phobic User (or one that is not very technology literate): These users

possess very little technology skills, or may even be intimidated by technology.

A Young Student: These users have most likely grown up with many gadgets,

though they may not necessarily be gadget lovers. Their knowledge of computer

interfaces will mostly likely be higher than average.

A Gadget Enthusiast: These users will most likely be the most proficient at

understanding and operating different computer and gadget interfaces. As such

they will also be the most demanding and discerning users.

A Long Commuter: These users may not necessarily be technologically inclined,

but they should be familiar with using a multitude of regular automobile functions

as they spend a lot of time driving.

An Elderly Driver: These users may not have the same dexterity as the average

user and will most likely have less technology experience as well.

Evaluation Protocol

The users will be asked to perform a variety of tasks on both the BMW X5’s

navigation system and the Digital Dashboard. The Digital Dashboard will be

implemented with the aforementioned prototype and will be operated through a Tablet

PC to simulate the touch screen aspect of the system. The BMW X5 will be supplied for

testing by one of our group members. In order to simulate a driving environment when

testing the Digital Dashboard, a driving video game will be used. This can be done either

in an arcade or with a television, a home video game console, and a steering wheel

controller.

Almost all of the users we will survey and study will not have any prior

experience using the BMW X5’s navigation system. They will most likely not have seen

our Digital Dashboard concept either. Therefore, we will start the evaluation by

comparing the time it takes to learn new functions and understand the way the interface

works. This will be achieved by supplying the user with a list of tasks they need to find

and perform such as:

Play a song with the CD Player

Change the CD track

Change the volume

Switch to the radio

Switch to the navigation screen

The time it takes to perform these tasks will then be recorded for both the BMW X5’s

navigation system and the Digital Dashboard. The second quantitative test will be

similar, but will be performed once the users have been given ten additional minutes to

familiarize themselves with the system. They will again be given a task list such as:

Play a CD track

Change the volume from a low to a medium setting

Save a favorite station for the radio

Tune to three different radio station

Set the CD playback to “SHUFFLE”

Switch between the CD playback and navigation screen

The users will be timed for each task on the list. Afterwards the data will be compiled

and studied with the statistical methods outlined in class. The final evaluation will be

with the video game setup. The user will be required to perform tasks while simulating

driving. The user will have to continuously keep the car in motion while also avoiding

obstacles in the game. We will record how many driving mishaps the user has while

navigating through a list of tasks and driving. This test will only be performed once the

users have familiarized themselves with the system. This way we hope that they will

utilize the quick motions and short-cuts. We estimate that we will be able to get a hold of

5 real users to carry out these evaluations.

C1 SUBJECTS Our test subjects can be divided into 2 categories: Technically inclined users and non-technical inclined users. Technically Inclined Users: The technically inclined users are defined as users that have experience using gadgets and are open to new technology. Non-technically Inclined Users: The non-technically inclined users are defined as users that are not open to new systems or interfaces. They like to live in their comfort zones and would go to great extents to avoid disruption of their equilibrium. Two of our users in pass 2 are same as pass 1. This implied that they had a greater sense of our system background, and had more input to our second iteration. They were more familiar with the system than other users and were more comfortable operating the Digital Dashboard since this was the second time they were exposed to it. We used 8 test users

User 1: Our first user is a middle-aged, 50, business professional who is technically inclined. He has a background in architecture but was not exposed to computer technology till last the 5 years. He does not mind learning new systems and is familiar with the BMW X5’s dashboard. He likes to use the complete functionality of the system. User 2: Our second user is a middle-aged woman around 50. She is a painter and does not like her equilibrium to be disturbed. Her main priority is music and is not motivated to use the navigation system. User 3: Our third user is a student in the ECE department. He is very technically inclined and likes the idea of state-of-art technology in his cars. He prefers to use all functionalities built into the system. User 4: The fourth user is a student in the faculty of Arts. She is not very technically savvy. She is open to new systems as long as they are easy to learn and add value to her experience. User 5: The fifth user is not a technically inclined student from the faculty of fine arts. He however uses some gadgets like mp3 player and cell phone. User 6: The sixth user is technically inclined ECE student. He owns a lot of gadgets and always carries his laptop. He keeps up to date with new technologies in the market and new developments and research advancements in the field of computers. User 7: The seventh user is a grad student in her early twenties in the faculty of arts. She is not very technically inclined but does use gadgets like cell phone. She however is not aware of most of the functionality in her cell phone besides the basic use. Her main priority in music and is inclined to learn the use of a GPS system as well.

User 8: The eighth user is 20-something technically inclined ECE student. He owns a lot of gadgets and always carries his laptop. He is comfortable learning new technology and has recently bought a PDA to go along with the usual iPod, apple laptop and high end cell phone.

C2 Evaluation Results Controlled User Study Sub-report Overview Our User Study is primarily a comparison between the BMW X5’s media and navigation system and the Digital Dashboard. The comparison will concentrate on testing the overall understandability of the system and will also test the efficiency of some of the functions. Because of the large scope of the project, we did not concentrate on implementing, prototyping and testing every single design aspect of the Digital Dashboard. Since we are more interested in comparing the overall design philosophies, such as the Digital Dashboard’s absence of modes and copious menus versus the X5’s multilayered interface, we felt that such an approach would allow us to evaluate from a much higher level and not get bogged down with details. Hypotheses:

Null Hypotheses 1 - It takes more time for a beginner to learn Digital Dashboard than to learn BMW X5’s Navigation system. Hypothesis 1 – It takes less time to become familiar with Digital dashboard, for a beginner, than with BMW X5’s navigation system. Null Hypothesis 2 – For an intermediate user, performing a set of tasks while concentrating on driving is easier and more efficient on the BMW X5’s system than the Digital Dash system Hypothesis 2 – For an intermediate user, performing a set of tasks while concentrating on driving is easier and more efficient on the Digital Dashboard system than then BMW X5’s system.

Independent Variables:

1) Digital Dash High Fed. Prototype 2) BMW X5’s Navigation System 3) Not technically inclined users 4) Technically inclined users

Dependent Variables:

1) The time it takes to take each required task

Experiment Task:

Part 1: The user is given a set of tasks to perform. The user is then given the Digital Dash system for the first time, and the observer will record the time it takes to finish each task. The BMW X5’s system is then presented to the user for the first time. He/She is ordered to perform the same set of tasks on the BMW system. The timing for each task is recorded for our statistical analysis. The list of tasks is as follows: 1. Play a new song with the CD Player 2. Change the CD track (Next Track) 3. Change the volume 4. Switch to the radio 5. Switch to the navigation screen

(Note: Refer to Appendix for all the Quantitative test forms)

Part 2: Given that the users have spent some time with the system, we will now test how easy it is for the users to perform the same set of tasks on the two different systems. This is all conducted while the user is concentrating on a main task (which would be playing a racing game on a laptop and therefore simulating real driving experience). 1. Change the CD track 2. Change the volume from a high to a low setting 3. Go to a favorite radio station (saved station) 4. Go from FM radio to AM or vice versa 5. Set the CD play list to “SHUFFLE” 6. Go to the navigation screen (Note: Refer to Appendix for all the Quantitative test forms)

Prototype:

We will be using the latest Digital Dash high fidelity prototype on a tablet PC. We will also be using the real BMW X5 navigation system.

Experiment Design:

For our experiments we had a total of eight users, divided into two categories: Technically inclined people and not technically inclined people. All of our studies were performed in a controlled environment set up in a BMW X5 car. For the first

part of the tests, users were given individual systems and were timed. In the second part, users were given a racing game and while they concentrated on the game play, they had to perform a set of tasks on each system. These results are recorded as well and at the end used in our analysis.

Data Collection:

The controlled user study was conducted in the BMW X5, on UBC campus parking lot # B4. Eight people were used, 4 of which being technically inclined and 4 being non technical.

Results: BMW X5 Test Times:

Task Times (s) Subject 1

Subject 2

Subject 3

Subject 4

Subject 5

Subject 6

Subject 7

Subject 8

TEST 1 Play a new song with the CD Player

7 6 17 2 4 14 13 10

Change the CD track (Next Track)

5 7 2 24 7 4 3 3

Change the volume 4 4 2 2 2 2 5 2 Switch to the radio 6 13 5 5 5 4 13 4 Switch to the navigation screen

10 7 11 35 15 15 12 9

TEST 2 Change the CD track 4 4 21 10 6 8 3 3 Change the volume from a high to a low setting

2 2 3 2 3 4 5 2

Go to a favorite radio station (saved station)

9 7 4 5 8 7 6 4

Go from FM radio to AM or vice versa

4 5 6 2 3 4 11 5

Set the CD play list to “SHUFFLE”

20 8 15 8 10 12 14 10

Go to the navigation screen

8 9 14 5 7 13 12 8

Digital Dashboard Test Times:

Task Times (s) Subject 1

Subject 2

Subject 3

Subject 4

Subject 5

Subject 6

Subject 7

Subject 8

TEST 1 Play a new song with the CD Player

30 30 7 4 6 6 17 6


4 10 6 6 5 6 5 5

Change the volume 15 4 5 4 5 4 8 5 Switch to the radio 2 15 4 2 3 5 3 7 Switch to the navigation screen

5 1 4 2 3 5 4 3

TEST 2 Change the CD track 5 3 7 5 4 6 4 6 Change the volume from a high to a low setting

2 2 13 5 5 8 5 5


7 3 11 4 6 11 11 6


5 6 10 4 5 5 4 6


15 3 10 15 8 15 8 4


1 1 3 3 3 3 2 2

ALL SUBJECTS TECHNICALLY INCLINED SUBJECTS NON-TECHNICALLY INCLINED SUBJECTS

Task Times (s) BMW Average Times

DD Average Times

BMW Standard

Dev

DD Standard

Dev

BMW Average Times

DD Average Times

BMW Standard

Dev

DD Standard

Dev

BMW Average Times

DD Average Times

BMW Standard

Dev

DD Standard

Dev TEST 1 Play a new song with the CD Player

9.125 13.250 5.249 11.068 11.750 12.250 4.787 11.843 6.500 14.250 4.796 14.250


6.875 5.875 7.160 1.808 4.000 6.750 2.160 2.217 9.750 5.000 9.639 5.000

Change the volume 2.875 6.250 1.246 3.770 2.500 4.500 1.000 0.577 3.250 8.000 1.500 8.000 Switch to the radio 6.875 5.125 3.834 4.324 6.500 7.750 4.359 4.992 7.250 2.500 3.862 2.500 Switch to the navigation screen

14.250 3.375 8.828 1.408 10.500 3.250 3.416 1.708 18.000 3.500 11.518 3.500

TEST 2 Change the CD track 7.375 5.000 6.046 1.309 9.000 5.500 8.287 1.732 5.750 4.500 3.096 4.500 Change the volume from a high to a low setting

2.875 5.625 1.126 3.543 2.750 7.000 0.957 4.690 3.000 4.250 1.414 4.250


6.250 7.375 1.832 3.249 5.500 7.750 1.732 3.948 7.000 7.000 1.826 7.000


5.000 5.625 2.726 1.923 5.000 6.750 0.816 2.217 5.000 4.500 4.082 4.500


12.125 9.750 4.086 4.892 11.250 8.000 2.986 5.598 13.000 11.500 5.292 11.500


9.500 2.250 3.162 0.886 11.000 2.250 2.944 2.250 8.000 2.250 2.944 2.250

Graphs:

TEST#1:

ALL TESTS Average Times

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TEST # 2

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T-Test:

Adjusted Means (s)

Sub 1 Mean

Sub 2 Mean

Sub 3 Mean

Sub 4 Mean

Sub 5 Mean

Sub 6 Mean

Sub 7 Mean

Sub 8 Mean

Mean Std Dev

SE T value

T Dist 1 T Dist 2

TEST 1

Play a new song with the CD Player

-11.50 -12.00 5.00 -1.00 -1.00 4.00 -2.00 2.00 -2.06 6.47 2.29 -0.90 0.19867726 0.39735452


0.50 -1.50 -2.00 9.00 1.00 -1.00 -1.00 -1.00 0.50 3.58 1.26 0.40 0.35212321 0.70424642

Change the volume -5.50 0.00 -1.50 -1.00 -1.50 -1.00 -1.50 -1.50 -1.69 1.62 0.57 -2.94 0.01088050 0.02176100 Switch to the radio 2.00 -1.00 0.50 1.50 1.00 -0.50 5.00 -1.50 0.88 2.07 0.73 1.20 0.13495511 0.26991021 Switch to the navigation screen

2.50 3.00 3.50 16.50 6.00 5.00 4.00 3.00 5.44 4.62 1.63 3.33 0.00628645 0.01257290

TEST 2

Change the CD track -0.50 0.50 7.00 2.50 1.00 1.00 -0.50 -1.50 1.19 2.64 0.94 1.27 0.12235212 0.24470423 Change the volume from a high to a low setting

0.00 0.00 -5.00 -1.50 -1.00 -2.00 0.00 -1.50 -1.38 1.66 0.59 -2.34 0.02601306 0.05202613


1.00 2.00 -3.50 0.50 1.00 -2.00 -2.50 -1.00 -0.56 1.97 0.70 -0.81 0.22315338 0.44630676


-0.50 -0.50 -2.00 -1.00 -1.00 -0.50 3.50 -0.50 -0.31 1.62 0.57 -0.54 0.30161271 0.60322542


2.50 2.50 2.50 -3.50 1.00 -1.50 3.00 3.00 1.19 2.42 0.86 1.39 0.10380250 0.20760499


3.50 4.00 5.50 1.00 2.00 5.00 5.00 3.00 3.63 1.58 0.56 6.51 0.00016583 0.00033167

N: 8 df: 7

Discussion and Analysis:

One major reoccurring theme in the graphs is that, for simple tasks, both BMW X5’s system as well as Digital Dashboard system perform equally well. By looking at the graphs, one can clearly see that tasks such as change music or change volume are performed within the same time frame on both systems. People who are more technically inclined performed actually better on the BMW X5’s system for such simple task. This conclusion is further fortified by looking at the T tests results for the same simple tasks. According to our calculations, T-test results for ‘Playing a new song’ or ‘Change the CD track’ are high number, which simply means that results from both system are so similar that there is little distinction between them We believe that there is a simple explanation as to why digital dashboard doesn’t perform much better in these tasks. Most subjects, during the test process, used the provided physical buttons for such tasks. That enabled them to perform the required action in an efficient way. Since in our prototype, we did not make any physical buttons, the same tasks had to be done through the GUI. As we had discussed before, we do plan to have some physical buttons on the steering wheel, as well as around the system’s screen. Overall, just the mere fact that both systems performed within the same range should actually encourage us that going through our menu system performed at the same level of efficiency as using real buttons.

The other major theme that is readily observed throughout our numbers and graphs is the fact that other non trivial tasks, such as going to the navigation screen are performed much faster on the digital dashboard system. On most graphs, one can clearly see how the yellow bars that represent Digital Dashboard are much smaller than BMW X5 bars, for tasks such as ‘Going to the Navigation Screen’. According to the T-tests calculations, are numbers for such tasks are miniscule, which implies that our two different systems are really distinct in behavior for such tasks. There is a simple explanation for these results. As we expected all along, for tasks that BMW has not provided simple buttons and users have to actually go through the menu interface, Digital Dashboard really reveals its advantage. This simply is due to our simple two layered implementation of the menu system. While for the BMW system, users have to go through numerous menus to get to an important function such as displaying the map, in Digital Dash one can simply achieve the same result by pressing the map area, only once, and the same result is achieved. Overall, these results confirm most of our hypotheses and reject our null hypotheses. One can conclude that on average:

1. It takes less time to become familiar with Digital dashboard, for a beginner, than with BMW X5’s navigation system.

2. For an intermediate user, performing a set of tasks while concentrating on driving is easier and more efficient on the Digital Dashboard system than then BMW X5’s system.

C3 Final Design Rationale:

The Digital dashboard concept, after numerous iterations in the prototyping process, has shaped up to be, overall, a well thought out design that effectively addresses some of the major problems of BMW X5’s navigation system. Our unique two layered menu system, combined with direct manipulation of the screen through the employment of touch screen technology, has proven its value through our various quantitative and qualitative studies. Overall, according to our studies, people find the digital dashboard a well designed, engaging and simple system which is relatively efficient to use. In most of our data analysis, it is evident that many tasks that involve going through more than one submenu in BMW are much more efficient in our digital dashboard system. It is therefore safe to conclude that our overall approach with respect to this system has been validated. Major strengths of the system are due to its simple two layered menu system as well as having universal access to the system’s functionality through the main screen.

That said, our tests have revealed some weaknesses in our system. One major theme in all of our studies is that functionalities - such as change of track or change of volume - that are easily done on the current BMW system by using buttons are less efficient in the Digital Dash system. This came as no surprise to our team since we knew that our system would probably need few shortcut physical buttons on the final product. We had already discussed how the physical buttons on the steering wheel would stay there, but now we think that we might at least need ‘change track’ buttons and ‘volume’ on our system so that a user on the passenger seat can use the buttons as well. We also realized that as users became more used to each system, some functions such as playing saved radio stations, are faster on the BMW X5’s system. This again is not surprising since we knew that by making all options equally available from the same menu system, some quicker functions on the old system would become a bit slower on our system. We believe that this is a good trade off since, on average, most important functionalities are quickly accessible from our main screen. We can also claim that most functionality is accessed in a more consistent time frame on the Digital Dashboard interface. The majority of the problems with the digital dashboard system are addressable through minor changes.

In addition to adding a few quick shortcut physical buttons, we believe that the overall system needs to be polished a bit more so that users find it even more engaging and understandable. Through our observations, while watching users interacting with the system, we realized that they recognized pictures such as ‘volume’ much more readily as an icon than symbols like the ‘CD playback’ (STOP, PAUSE, BACK, PLAY, FORWARD on the bottom of the screen). Some users initially wanted to tap on the small next button - at the bottom of the screen - to change the track, instead of waiting for the pop up screen to fully open. This is an easy fix, which can be addressed by simply putting one big icon instead of those symbols (STOP, PAUSE, BACK, PLAY, and FORWARD) on the main screen. The last major issue we found was that some people -particularly the

less technically inclined people - did not fully understand the use of play-list screen. Subjects that were more technically inclined, though, found this screen very useful.

Overall, we think that digital dash successfully passed important aspects of our

tests, while much useful insight was revealed by other data. One needs to take into consideration that due to prototyping limits, the tests were less fair towards digital dash system. In our test environment, users had to use the tablet PC pen instead of their finger tips - as their only interaction mechanism with the system. Since the existing BMW X5 system is a final product, such limitations were not suffered by the system during the experiments. All this gives us enough confidence to declare the overall system a success. The next major step is to make a last prototype that has more functionality and takes into account the minor changes that we have recommended. After that, we feel that this system will be ready to be fully implemented and released to the targeted market.

Over the course of our design process, during pass 1 and pass 2, once we identified our goals for the system, our major design rationale has never changed. What we set out to accomplish was to make an in car navigation/multimedia system easier to use while keeping it relatively efficient. At the core of our system, the innovative two layered menu system, withstood the entire prototyping/analysis process. Along the way, through much needed heuristic evaluations and user studies, smaller but yet important aspects of our design were refined. It is therefore safe to say that our design rationale has overall stayed the same, while applied changed has made it a much more realistic, robust and effective system. Our team strongly believes that this system can eventually materialize as a real solution which addresses a real problem.

C4 Reflection on our Design Process:

For all members of our team this EECE 418 project is our introduction to user-

centered designed. Up until this point we have generally created projects that are system feature centric. The interface has usually been a secondary concern. After working on this project we came to appreciate the relationship between the user and the interface a great deal more. The user will interact with the interface and not the underlying system. If the interface does not provide good mental models and does not facilitate efficient interactivity then a lot of the effort spent on the underlying functionality is lost to a certain degree.

The BMW X5’s interface is a great example of this. It has many useful and robust functions; however, several of important functions are only accessible through multi-layered menu systems. Users are often left confused as how to enter the many different modes of operation. The emphasis in the BMW’s system seems to be on having as much functionality as possible. Though many of the functions are great, there is a point of diminishing returns because of the complex interface. Each additional function after a certain point adds a great deal of complexity to accessing the rest. System functions seem to be given precedent over usability and because of this many users don’t end up taking advantage of the features, as it is too troublesome to wad through the interface to find them.

When we initially started studying the BMW X5 we could feel that it wasn’t user-friendly, but we couldn’t quite put our finger on why it wasn’t user friendly. Our first instinct was just to put in some extra functions which we thought would help usability, such as a touch screen interface. We just thought throwing some technology around would help the problem. Although it turns out that this is a desirable feature and does enhance usability, it only addressed a part of the problem. When we analyzed the system with user-centered design and started making our first few paper prototypes, we realized that the BMW X5’s system simply demands too much from its users. Since in-vehicle systems are ideally supposed to assist drivers, we felt that it was counter-productive to have the user work hard to operate a system which is designed to make his/her life easier. Through a few iterations and some analysis techniques, such as cognitive walkthroughs and heuristic evaluations, we came up with a system whose first and foremost goal was to help the driver. Tools such as the touch-screen interface and helpful animations simply became fitting means to this end. Some of the biggest insights to improve our design once we had come up with our initial prototypes were made by external groups and evaluators. The heuristic evaluators and the session with Dr. Fels and Kyle really helped pinpoint some issues that the group may have overlooked during the design process. We think it would have been advantageous to have more user involvement from general test subjects earlier in the project, but we realize that time constraints don’t make this practically feasible. The feedback and criticism we received was always constructive.

For our particular project, we felt that the paper prototypes provided not only the easiest and most practical method of interface design and refinement, but also the most useful. It really allowed us to concentrate on the concepts and philosophies of different interfaces without considering the nuts and bolts. This in turn allowed a lot of different ideas to be seriously evaluated.

The most difficult part of the process was the final user evaluation and comparison with the BMW X5. Finding users that fit within our notion of a ‘representative user’ was quite difficult. Running a completely controlled and fair comparison also presented some difficulties. The prototype we made was fully functional for the test we wanted to perform, but we had to improvise a lot of the features. For instance, instead of having a true touch screen we had to make due with a tablet PC pen.

The concepts and design approaches we learned in 418 will most likely be very useful to us when we work on future computer interface intensive projects. The course has given us wide range of tools and ideas to draw upon instead of just going with our gut instincts when doing interface design.

team execution pass 2 report: bmw x5’s digital...

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