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1. Respondents said they have been working in their current occupation anywhere from 1 year or less to 38 years with an average of 17 years See Figure 1 Thus many of the staff received their formal academic training in the pre computer era 12 RANGE IN RANGE years each X 1 person 0 1 5 XXXXX 2 3 21 XXXXXXXXXXXXXXXXXXXXX 4 5 8 XXXXXXXX 6 7 4 XXXX 8 9 i X 10 11 4 XXXX 12 13 2 XX 14 15 6 XXXXXX 16 17 4 XXXX 18 19 9 XXXXXXXXX 20 21 9 XXXXXXXXX 22 23 18 XXXXXXXXXXXXXXXXXX 24 25 4 XXXX 26 27 2 XX 28 29 6 XXXXXX 30 31 9 XXXXXXXXX 32 33 4 XXXX 34 35 4 XXXX 36 37 1 X 38 39 1 X Sample 122 missing 0 FIGURE 1 DURATION OF EMPLOYMENT IN CURRENT FIELD Table 7 shows the job tasks that participants perform both with a computer and manually Of particular significance is that 61 of the respondents do not currently use a computer on the job Of the categories for which a computer is used the most common task is digitizing one which follows a rather fixed routine Interestingly word processing the most common task in offices is performed quite infrequently Clearly many of the potential users of the CAD system are novices in the truest sense of the term One therefore cannot expect users to be able to rely upon insights from other systems to solve interaction problems 13 TABLE 7 JOB TASKS Using a Computer Don t use a computer on my job 73 61 3 Word processing 6 5 0 Prepare spreadsheets 4 3 4 Digit
2. Technical Report Documentation Page 1 Report No 2 Govemment Accession No 3 Recipient s Catalog No er ee 4 Title and Subtitle 5 Report Dote 6 Performing Organi zation Code 8 Performing Organi zation Report No 7 Author s UMTRI 87 15 9 Performing Organization Name and Address 10 Werk Unit No The University of Michigan le Transportation Research Institute 11 Contract or Grant No 2901 Baxter Road Ann Arbor MI 48109 2150 U S A 13 Type of Report and Period Covered Interim 12 Sponsoring Agency Neme ond Address Chrysler Motors Corporation Sept 1986 Feb 1987 14 Sponsoring Agency Code R amp D Programs Administration Chrysler Acct 2000531 Who Are the Potential Users of a CAD System 12000 Chrysler Drive Highland Park MI 48288 1118 15 Supplementary Notes Supported by the Chrysler Challenge Fund 16 Abstract This report describes a survey of the potential users of a T aided surfacing system That system to run on Evans and Sutherland PS 300 workstations will be used to develop the body and interior surfaces for future vehicles The 7 page 24 question survey was distributed to all employees of the Chrysler Motors Product Design Office in Highland Park Michigan Fromthe 240 people in the office 122 completed surveys were obtained The key finding was that while the respondents had considerable job experience average of 17 years and were reasonably well educated al
3. Participants also reported what they studied in school See Table 1 The most popular areas of study were design 38 and engineering 29 mostly mechanical engineering When developing software programmers tend to think of the users as being like themselves That is clearly not true here ene a SP SS A TABLE 1 AREAS OF STUDY Area of Study First Second Third Engineering 4 4 0 1 3 1 O Mechanical Engrg 22 22 2 1 3 1 O Civil Engrg 1 1 0 O O Electrical Engrg O 1 3 1 O Materials Engrg O O 1 9 1 Automotive Engrg 1 1 0 O O Packaging Engrg 1 1 0 O O Architecture O 1 3 13 O 29 29 2 4 12 5 1 9 5 Business 1 1 0 3 9 4 O Management 1 1 0 1 3 1 O Marketing 2 2 0 O 1 9 1 Industrial Mgmt 1 1 0 O O Advertising O 1 3 1 1 9 1 Real Estate O 1 3 1 O 5 51 6 18 8 2 18 2 Fine Arts 7 7 1 O 3 27 3 Graphics 6 6 1 4 12 5 1 9 1 Sculpture 2 2 0 3 9 4 O 15 15 2 7 21 9 4 36 4 Design O O Industrial Design 35 35 4 7 21 9 O Automotive Design 3 3 03 2 6 3 1 9 1 BIW Design 0 O 1 9 1 38 38 4 9 28 1 2 18 2 Other Technical 5 5 13 4 12 5 1 9 1 Drafting 4 4 0 1 3 1 O 9 9 1 5 15 6 1 9 1 Other 3 3 0 1 3 1 1 9 1 Sample 99 32 11 missing 23 90 111 First is the primary area of study their major Second is their second area of study a minor Table 2 shows how much forma
4. 1984 Preliminary Design of the Ford TM 3 Tripcomputer The University of Michigan Transportation Research Institute technical report UMTRI 84 6 Ann Arbor Michigan March Mantei M 1986 Techniques for Incorporating Human Factors in the Software Lifecycle Proceedings of the Structured Techniques Association Third Annual Conference 177 203 Norman D A 1981 The Trouble with UNIX Datamation November 139 150 22 Poor A 1986 Screen Test Software for the Image Makers PC Magazine December 23 5 22 199 220 Taylor J 1987 personal communication 23 APPENDICES 24 APPENDIX A SURVEY FORM HUMAN FACTORS DIVISION Ms Susan Adams and Dr Paul Green 313 764 4158 INTRODUCTION This survey is being conducted by the University of Michigan Transportation Research Institute for the Chrysler Corporation Chrysler is planning to implement a new Computer Aided Surfacing CAS system which will be used to design interior and exterior car surfaces The University is helping to develop the user interface for this system The purpose of this survey is to determine the background of potential users of this new system so that a user friendly interface can be developed Since you are a potential user we would like to customize the system to fit your background This Survey will NOT be used to select the users of the CAS system Chrysler will be given only the combined data from those surveye
5. 118 missing 4 The 39 people who have used a mouse represent 33 1 of the sample 118 who responded to question 14 Two of the people who responded to question 14 did not respond to this question They represent 53 4 of the 73 people who responded to this question Since more than one choice was available percentages will not total 100 Eighteen of 48 respondents said they were most comfortable using a mouse aS a pointing device Cursor keys were the next favorite 7 of 48 Thus if a single cursor control device must be chosen user preference would indicate a mouse as the best choice Performance data in the human factors literature suggest it is often a best choice as well Card English and Burr 1978 However if a mouse is selected most users will need training on how to use it When asked which hand they preferred to use with a pointing device 58 responded right hand 4 left hand 9 either hand These responses are in line with an earlier question about handedness In that question to which the full sample responded 82 8 said they were right handed 10 7 left handed and 6 6 ambidextrous These figures correlate closely with the handedness of the general population Given the fair number of lefties users should be able to locate input devices such as mice and dials on either side of the keyboard However if that is not possible then input devices should be located on the right Finally only
6. 55 63 who responded 43 9 not attending 72 62 6 72 88 9 100 0 100 0 100 0 100 0 Sample 115 81 missing 7 41 The 4 people who attended a management seminar represent 3 5 of the smaple 115 who responded to question 6 One person who answered yes did not list a seminar type They represent 9 3 of the 43 people who responded to this question To put these numbers in context shown in Table 4 are the employment figures for the big three automakers in 85 1986 figures are not yet available and the number of people attending engineering short courses at the University of Michigan in 86 Those courses cover topics of interest to automotive engineers and designers and many concern computers The data shown are fairly typical of the 1979 1986 time period Relative to the other manufacturers the number of people sent by Chrysler is quite low It may be that as a consequence they have less exposure to new technology such as computers than their competitors 10 TABLE 4 SHORT COURSE ATTENDANCE Company Employee 1985 1986 Short Course Category Employment Attendance Chrysler Total 84 804 4 Hourly 60 231 Ford Total 184 700 45 Hourly 116 900 GM Total 564 685 105 Hourly 431 199 Total All Companies 1079 Sources The employment figures were compiled by Dave Andrea of the UMTRI staff from corporation annual and public reports Andrea 1987 The short course data came from Joe Taylor of the Univers
7. Designing computer displays for those that wear bifocals is particularly difficult especially for large screen systems such as the PS 300 Bifocals are most useful when the material to be read is close low in the visual field and of a relatively small area Problems with bifocals can be reduced by minimizing the number of vertical eye movements by placing instructions and menus at the bottom of the screen and by providing users with special reading glasses How Much Education Do Users Have From educational data one can make inferences about the users reading level and vocabulary which influence how help files error messages and documentation are written and about the concepts with which users will be familiar Often explanations are built around analogies This device works just like a __ when you Those explanations will be meaningful only if the analogies are familiar In this case 9 8 of the respondents indicated that they had only completed high school 9 8 attended technical vocational school 35 2 completed some college 37 7 had graduated from college and 7 4 had attended graduate school Since well over 90 of those responding have completed high school and over 2 3 some college it is Safe to assume users will understand material written at a 12th grade reading level Even more notable than the minimum level of education is the range in the levels of education from high school all the way to graduate school
8. 59 1 97 1 who responded 70 who have not used a computer 45 39 1 100 0 100 0 Sample 115 missing 7 The 2 people who have experience with speech input represent 1 7 of the sample 115 who responded to question 14 5 people who responded to question 14 did not respond to this question They represent 2 9 of the 70 people who responded to this question THANK YOU FOR YOUR TIME
9. years for the sample mean 2 1 yrs min 0 max 16 sample 100 missing 22 see note below for computer users mean 3 8 yrs min 1 max 16 std dev 3 9 sample 55 see note below 20 people who responded yes to question 14 did not respond to this question Do you use a computer at home RESPONSES see note below Yes 17 14 7 23 9 No 54 46 6 76 1 who responded 71 who have not used computers 45 38 8 100 0 100 0 Sample 116 missing 6 The 17 people who do use a computer at home represent 14 7 of the sample 116 who responded to question 14 4 of the people who responded to question 14 did not respond to this question They represent 23 9 of the 71 people who responded to this question 17 38 Below is a list of computer hardware In the left column check all those that you have used either at work or at home In the right column check all those that you use at least once per week Hardware have used once per week see note below see note below IBM PC compat 19 18 8 33 9 7 6 9 12 5 Apollo 1 1 0 1 8 1 1 0 1 83 LISP AI machine 4 4 0 7 1 2 2 0 3 6 Ctrl Data Tek 28 27 7 50 0 14 13 9 25 0 Ctrl Data E amp S 13 12 9 23 2 6 5 9 10 7 Sun 3 3 0 5 4 1 1 0 1 83 Apple II 11 10 9 19 6 O Macintosh 6 5 9 10 7 2 2 0 3 6 Commodore 64 11 10 9 19 6 O Cyber 205 4 4 0 7
10. 17 computer users have had any experience with a windowing screen format and only 2 have ever used systems with speech input 19 CONCLUSIONS While one could label this group of potential users as naive and leave it at that a more detailed description of the users is necessary Just as one needs specifics about the power supplied the operating temperature of the equipment and so forth one also needs specific information about the users Trying to design a computer system for users is like trying to design a computer when all one knows is that it will be powered by electricity Is it AC or DC What voltage How much current Narrowing the choice for example by saying it is for novices is like saying the computer will run on alternating current But is it 110 or 220 Square wave or sine wave Is the source reliable or is a backup power supply needed etc Without this specific information there is a strong tendency for system developers to view users as being like those they know best namely themselves It is unlikely a system developed with that perspective will be easy for novices to use Therefore it is imperative that detailed information concerning the user population be collected and made available to system developers The survey discussed in this report addressed five key questions about candidate users How well do users see About one quarter of potential CAS users wear bifocals As discussed previously thi
11. IBM or similar Mainframe IBM Series 36 38 other s Below is a list of operating systems In the left column check all those that you have used either at work or at home In the right column check all those that you use at least once per week have once used per week PC DOS MS DOS PRO DOS UNIX VM CTOS Macintosh User Interface NOS BE MTS MULTICS other s 19 20 21 22 29 Below is a list of computer applications In the left column check all those that you have used either at work or at home In the right column check all those that you use at least once per week have used EH H AHL TI once per week word processing business graphics e g pie charts histograms spreadsheets artwork e g MacPaint statistics data base management programming Chrysler CADCAM other CAD CAM programs not Chrysler games other s Which pointing devices have you used check all that apply mouse joystick cursor keys touchscreen tablet digitizer track ball bowling ball dial knob thumb wheel light pen other s Which pointing device are you most comfortable with Which hand do you prefer to use with a pointing device check one right hand left hand either hand 23 24 30 Do you have any experience with windowing as a type of screen display format as used on the Apple Macintosh Yes No Do you have any experience with computer systems that u
12. 1 2 2 0 3 6 Cray 1 1 0 1 8 1 1 0 1 8 VAX MicroVAX 2 2 0 3 6 1 1 0 1 8 IBM Mainframe 7 6 9 12 5 2 2 0 3 6 IBM Series 36 38 5 5 0 8 9 2 2 0 3 6 other s 16 15 8 28 6 4 4 0 7 1 who responded 56 who have not used computers 45 44 6 Sample 101 missing 21 The 19 people who have used an IBM PC represent 18 8 of the sample 101 that responded to question 14 19 people who responded to question 14 did not respond to this question They represent 33 9 of the 56 people who responded to this question Since more than one choice was available percentages will not total 100 39 Below is a list of operating systems In the left column check all those that you have used either at work or at home In the right column check all those that you use at least once per week Op Systems have used once per week see note below see note below PC DOS MS DOS 17 24 6 70 8 6 8 7 25 0 PRO DOS 1 1 4 4 2 1 1 4 4 2 UNIX 1 1 4 4 2 O VM 2 2 9 8 3 2 2 9 8 3 CTOS 1 1 4 4 2 1 1 43 4 2 Macintosh 4 5 8 16 7 2 2 9 8 3 NOS BE 4 5 8 16 7 4 5 8 16 7 MTS 2 2 9 8 3 1 1 4 4 2 MULTICS 1 1 4 4 2 1 1 4 4 2 other 5 7 2 20 8 2 2 9 8 3 who responded 24 who have not used computers 45 65 2 Sample 69 missing 53 The 17 people who have used PC DOS MS DOS represe
13. 6 19 15 8 one finger 23 19 2 two fingers 35 29 2 more than two fingers but less than ten fingers 29 24 2 all ten fingers Sample 120 missing 2 Do you usually look at the keyboard when you type check one RESPONSES see note below yes 70 57 9 65 43 sometimes for numbers and letters 23 19 0 21 5 sometimes for numbers but not letters 8 6 6 7 53 no 6 5 03 5 6 who responded 107 who can t type 14 11 6 100 0 100 0 Sample 121 missing 1 The 70 people who look at the keyboard represent 57 9 of the sample 121 who responded to question 11 One person who did not respond to question 11 did respond to this question They represent 65 4 of the 107 who responded to this question Do you type fast enough to be a secretary RESPONSES see note below Yes 9 7 4 8 3 No 99 81 1 91 7 who responded 108 who can t type 14 11 5 100 0 100 0 Sample 122 missing 0 The 9 people who type fast enough to be a secretary represent 7 4 of the sample 122 who responded to question 11 Two people who did not respond to question 11 did respond to this question They represent 8 3 of the 108 who responded to this question 14 I5 16 3 7 COMPUTER SYSTEMS EXPERIENCE Have you ever used a computer 75 62 5 Yes 45 37 5 No gt do not answer questions 15 24 Sample 120 missing 2 How long have you been using computers
14. 6 18 8 2 18 2 fine arts 7 7 1 O 3 27 33 graphics 6 6 1 4 12 5 1 9 1 sculpture 2 2 0 3 9 4 O 15 15 2 7 21 9 4 36 4 design O O O industrial design 35 35 4 7 21 9 O automotive design 3 3 03 2 6 3 1 9 1 BIW design O O 1 9 13 38 38 4 9 28 1 2 18 2 other technical 5 5 13 4 12 5 1 9 1 drafting 4 4 0 1 3 1 O 9 9 1 5 15 6 1 9 1 other 3 3 03 1 3 1 1 9 13 Sample 99 32 11 missing 23 90 111 34 Have you recently attended any workshops seminars short courses 72 62 1 No 44 37 9 Yes gt What Sample 116 missing 6 SEMINAR TYPE FIRST SECOND see note below see note below management 4 3 5 9 3 1 1 2 11 1 communications 10 8 7 23 3 1 1 2 11 1 design 3 2 6 7 0 1 1 2 11 1 computers 2 1 7 4 7 1 1 2 11 1 other 24 20 9 55 8 5 6 2 55 63 who responded 43 9 not attending 72 62 6 72 88 9 100 0 100 0 100 0 100 0 Sample 115 81 missing 7 41 The 4 people who attended a management seminar represent 3 5 of the smaple 115 who responded to question 6 One person who answered yes did not list a seminar type They represent 9 3 of the 43 people who responded to this question OCCUPATIONAL INFORMATION What is your occupation check one O draftsperson 31 25 4 designer 1 0 8 technician O technical illustrator 44 36 1 artist sculptor O hu
15. 61 184 Bricklin D 1985 Dan Bricklin s Demo Program User Manual West Newton MA Card S K English W K and Burr B J 1978 Evaluation of Mouse Rate Controlled Isometric Joystick Step Keys and Text Keys for Text Selection on a CRT Ergonomics 21 8 601 613 Chrysler Motors Corporation and Evans and Sutherland Computer Corporation 1986 Chrysler Motors Corporation Evans and Sutherland Computer Corporation Corporate Research and Development Agreement confidential document November 1 1986 Gilb T 1985 The Impact Analysis Table Applied to Human Factors Design in Shackel B ed Human Computer Interaction INTERACT 84 Amsterdam Netherlands North Holland 655 659 Good M Spine T M Whiteside J and George P 1986 User Derived Impact Analysis As a Tool for Usability Engineering Human Factors in Computing Systems CHI 86 Proceedings April 241 246 Gould J D and Lewis C 1983 Designing for Usability Key Principles and What Designers Think CHI 83 Proceedings Human Factors in Computing Systems New York Association for Computing Machinery 50 53 Gould J D and Lewis C 1984 Designing for Usability Key Principles and What Designers Think IBM technical report RC 10317 Yorktown Heights New York Gould J D and Lewis C 1985 Designing for Usability Key Principles and What Designers Think Communications of the ACM 28 3 300 310 Green P
16. 7 0 Artwork 12 11 8 21 5 5 4 9 8 8 Statistics 5 4 9 8 8 2 2 0 3 5 Data Base Mgmt 7 6 9 12 3 2 2 0 3 5 Programming 11 10 8 19 3 5 4 9 8 85 Chrysler CADCAM 31 30 4 54 4 13 12 7 22 8 Other CAD CAM 7 6 9 12 3 1 1 0 1 8 Games 20 19 6 35 13 4 3 9 7 0 Other 2 2 0 3 55 1 1 0 1 8 who responded 57 who have not used computers 45 44 1 Sample 102 missing 20 The 26 people who have done word processing represent 25 5 of the sample 102 that responded to question 14 18 people who responded to question 14 did not respond to this question They represent 45 6 of the 57 people who responded to this question Since more than one choice was available percentages will not total 100 Participants were also asked which pointing devices they had used Their responses are shown in Table 11 Most common were cursor keys followed by the mouse and digitizer buttons on the mouse were not obtained Data on the number of 18 TABLE 11 POINTING DEVICE EXPERIENCE Devices Mouse 39 33 1 53 4 Joystick 22 18 6 30 1 Cursor Keys 46 39 0 63 0 Touchscreen 19 16 1 26 03 Tablet 13 11 0 17 8 Digitizer 34 28 8 46 6 Trackball Bowling Ball 7 5 9 9 6 Dial Knob 11 9 3 15 13 Thumb Wheel 20 16 9 27 4 Light Pen 16 13 6 21 9 of responses 73 who have not used a computer 45 38 1 Sample
17. at the information being requested would be used in designing the user interface to new software Also employees were told that all potential users of the new software were being asked to participate in the survey Finally supervisors instructed their employees to return completed surveys to the CAD CAM manager Mike Holmes The introduction section on the cover page contained similar instructions In addition it asked participants to take their time and answer the questions as completely as possible For the complete instructions see Appendix A Surveys were completed during working hours RESULTS AND DISCUSSION In many cases percentages have been used to summarize the data Where tables are discussed percentages have been rounded off to facilitate discussion Also questions may be discussed in a different order than they appeared in the survey Appendix B contains all the response data in the same order as the survey questions How Well Do Users See Of those responding 47 5 wear glasses 10 7 wear contacts and 23 8 wear bifocals Visual acuity ranged from 20 10 to 20 60 with a mean of 20 24 57 of the respondents reported having 20 20 vision Although most people reported they could see fairly well it is important to note that 49 of the 122 respondents did not know their visual acuity In addition the question was worded so that it was not clear whether participants should report corrected or uncorrected visual acuity
18. ave used once per week IBM PC compat 19 18 8 33 9 7 6 9 12 5 Apollo 1 1 0 1 8 1 1 0 1 8 LISP AI machine 4 4 0 7 1 2 2 0 3 6 Ctrl Data Tek 28 27 7 50 0 14 13 9 25 0 Ctrl Data E amp S 13 12 9 23 2 6 5 9 10 7 Sun 3 3 0 5 4 1 1 0 1 83 Apple II 11 10 9 19 6 O Macintosh 6 5 9 10 7 2 2 0 3 6 Commodore 64 11 10 9 19 6 O Cyber 205 4 4 0 7 1 2 2 0 3 6 Cray 1 1 0 1 8 1 1 0 1 83 VAX MicroVAX 2 2 0 3 6 1 1 0 1 83 IBM Mainframe 7 6 9 12 5 2 2 0 3 6 IBM Series 36 38 5 5 0 8 9 2 2 0 3 6 other s 16 15 8 28 6 4 4 0 7 1 who responded 56 who have not used computers 45 44 6 Sample LOL missing 21 The 19 people who have used an IBM PC represent 18 8 of the sample 101 that responded to question 14 19 people who responded to question 14 did not respond to this question They represent 33 9 of the 56 people who responded to this question Since more than one choice was available percentages will not total 100 Table 9 shows which operating systems participants have used The PC DOS MS DOS operating system has been used by more participants than any other however the number of missing responses 53 may indicate that most of the computer users do not know the names of the operating systems they have used Nonetheless it appears that users of the system be
19. ble percentages will not total 100 41 Which pointing devices have you used check all that apply Devices see note below mouse 39 33 1 53 43 joystick 22 18 6 30 13 cursor keys 46 39 0 63 03 touchscreen 19 16 1 26 0 tablet 13 11 0 17 83 digitizer 34 28 8 46 6 trackball bowling ball 7 5 9 9 6 dial knob 11 9 3 15 13 thumb wheel 20 16 9 27 4 light pen 16 13 6 21 9 other 7 O of responses 73 who have not used a computer _45 38 1 Sample 118 missing 4 The 39 people who have used a mouse represent 33 1 of the sample 118 who responded to question 14 Two of the people who responded to question 14 did not respond to this question They represent 53 4 of the 73 people who responded to this question Since more than one choice was available percentages will not total 100 42 Which pointing device are you most comfortable with Devices see note below mouse 18 19 4 37 5 joystick 4 4 3 8 33 cursor keys 7 7 5 14 6 touchscreen 1 1 1 2 1 tablet 2 2 2 4 2 digitizer 5 5 4 10 43 trackball bowling ball 1 1 1 2 13 dial knob 1 1 1 2 1 thumb wheel 4 4 3 8 3 light pen 5 5 4 10 4 other O of responses 48 who have not used a computer 45 48 4 100 0 100 0 Sample 93 missing 29 The 18 people who prefer a mouse represent 19 4 of the sample 93 who responded to qu
20. d not individual responses Take your time and answer the following questions as completely as you can If you have any questions concerning this Survey please contact Susan Adams or Paul Green at the above phone number or call Mike Holmes at 956 2106 Please see that this survey is returned to Mike Holmes We appreciate your cooperation in this effort 25 BIOGRAPHICAL INFORMATION Are you check one right handed left handed ambidextrous Do you wear check all that apply glasses contacts bifocals What is your visual acuity e g 20 20 EDUCATIONAL INFORMATION What is the highest level of formal education you have completed check one high school technical vocational school some college college graduate school Indicate special areas of study e g mechanical engineering industrial design graphic arts Have you recently attended any workshops seminars short courses No Yes gt What T0 26 OCCUPATIONAL INFORMATION is your occupation check one draftsperson designer technician technical illustrator artist sculptor human cannonball mechanical engineer electrical computer engineer other engineer gt what type not electrical computer or mechanical other is your job title How long have you been working in your current field What years tasks do you perform on your job check all that apply using a computer don t use a computer on m
21. date user population for one such system in great detail This work is part of a larger project originally titled User Interface for Robot Programming directed by Klaus Peter Beier of the University of Michigan Department of Naval Architecture and Marine Engineering This project was supported by the Chrysler Challenge Fund The authors would like to thank several individuals from Chrysler for their help with this work In particular Mike Holmes Manager of CAD CAM in the Chrysler Product Design Office Bob Antworth Supervisor for Distributed Graphics Development in the Engineering Office and Chris Wood of the Product Design Office staff INTRODUCTION This report describes research being conducted at the University of Michigan Transportation Research Institute for the Chrysler Corporation Design Office Specifically the University is helping Chrysler develop a user interface to a new Computer Aided Surfacing CAS system a special purpose Computer Aided Design CAD system The CAS system will be used to design body and interior surfaces for future vehicles This software will run on Evans and Sutherland PS 300 workstations This project came about because Chrysler recognized that the CAS software should be easy to use if their designers were to take full advantage of it In addition Chrysler has shown great interest in learning about how to apply human factors methods and principles to the design of user interfaces Those pri
22. e specific research is lacking and calculations are not possible 3 Translate the system functions into user activites This is the second half of the Gould and Lewis focus on users principle User activities might include loading files deleting lines in a text file rotating screen images in particular planes and so forth This step will be covered in the next report 4 Develop usability criteria Depending on the organization usability criteria may be used as either quality assurance levels or as design goals In terms of the design process these criteria are used for evaluating system prototypes and also for determining whether the final version is ready for release In line with Gould and Lewis call for empiric measurement these criteria should take the form of mean times and errors for benchmark tasks though subjective measures of user satisfaction may be included as well In developing the criteria specifications are required for test sample sizes conditions and so forth Bennett 1984 Gilb 1985 and Good Spine Whiteside and George 1986 all discuss this subject in detail 5 Develop alternative task methods It is at this stage that most consider the real design work to begin Issues that arise address the selection of input devices the interaction structure and Sequencing and so forth Phase 1 of this program what is funded so far assumes this is the last step to be completed 6 Analyze the alternative met
23. estion 14 27 of the people who responded to question 14 did not respond to this question They represent 37 5 of the 48 people who responded to this question Which hand do you prefer to use with a pointing device check one HAND see note below right hand 58 50 0 81 7 left hand 4 3 4 5 63 either hand 9 7 8 12 73 who responded 71 who have not used a computer 45 38 8 100 0 100 0 Sample 116 missing 6 The 58 people who prefer their right hand represent 50 0 of the sample 116 who responded to question 14 4 of the people who responded to question 14 did not respond to this question They represent 81 7 of the 71 people who responded to this question 29 24 43 Do you have any experience with windowing as a type of screen display format as used on the Apple Macintosh RESPONSES see note below Yes 17 14 9 24 6 No 52 45 6 75 4 who responded 69 who have not used a computer 45 39 5 100 0 100 0 Sample 114 missing 8 The 17 people who have experience with windowing represent 14 9 of the sample 114 who responded to question 14 6 of the people who responded to question 14 did not respond to this question They represent 24 6 of the 69 people who responded to this question Do you have any experience with computer systems that use speech as a method of input RESPONSES see note below Yes 2 1 7 2 9 No 68
24. from these data that their principles are not obvious Where Do These Principles Fit into the Development Process A computer system will be easy to use only if there is a deliberate effort to make it easy to use Such an effort requires money to support usability analyses and tests professionals trained in human factors and usability milestones in the schedule Details of the design process have been described elsewhere e g Mantei 1986 and are presented here in a modified form for convenience l Identify the purpose of the system For this project Chrysler has already defined the purpose of the CAS system This information along with a detailed description of the system functions appears in the CAS system specifications Chrysler Motors Corporation and Evans and Sutherland Computer Corporation 1986 2 Identify the users This step what Gould and Lewis call early focus on users is a topic covered in this report Quite simply it is not possible to develop a system that is well matched to the users without a detailed description of who they are When this information is not provided programmers tend to view the users as being just like themselves and assume users know and can do what they can This is rarely true These data can be used for making empiric predictions about user performance such as the time to type a command and can be used to evaluate design alternatives However their greatest value is in situations wher
25. han 10 fingers and 24 type with all 10 fingers Most of the participants 60 look at the keyboard when they type 19 look sometimes for numbers and letters 7 look sometimes for numbers but not for letters and 5 do not look at the keyboard When asked whether they could type fast enough to be a secretary 7 said yes and 81 said no Thus when using the Keystroke Model Card Moran and Newell 1983 to predict the times for interaction tasks such as the time to type commands interkeystroke intervals values for K in the 75 to 1 20 second range are appropriate What Computer Hardware and Software Are Users Familiar With While most respondents have not used computers at work many specifically 37 5 have never used computers Of those who have used computers the average amount of experience is 3 9 years with a low of 1 year or less and a high of 16 years Home computers are used by 14 7 of the participants 23 9 of the computer users Table 8 shows the types of hardware computer users are familiar with The machines used most frequently were the Control Data Tektronix and the IBM PC or compatible Half of the computer users 28 of 56 have been exposed to the Tektronix hardware and one fourth 14 of 56 use it at least once per week The IBM PC or compatible is used once per week by 7 of the 56 computer users while 19 have used it at least once 15 TABLE 8 HARDWARE EXPERIENCE see note below use at least Hardware h
26. hods At one time this could only be accomplished by carrying out experiments though sometimes the human factors literature was helpful Commonly expert judgement was also sought The approach now in favor is to use human performance models e g Card Moran and Newell 1983 to predict the performance of users These analyses can be used to eliminate the weaker candidate designs 7 Prototype test and modify This step is the heart of Gould and Lewis iterative design principle and critical to its success are prototyping tools System prototypes can be developed on personal computers using tools such as Dan Bricklin s Demo Program Bricklin 1985 or using the Wizard of Oz program being developed at the University of Michigan Green and Wei Haas 1985 to name some examples These prototypes should be formally tested by a small sample of users Based upon the empiric test data the design should be modified This process should be repeated again and again until the user performance criteria are met After the prototyping phase is complete the same cycle of tests and modifications should be carried out on versions of the working system What Do Developers Need to Know About Users As noted previously this report identifies the potential users of the CAS system The information was collected using a survey Particular issues addressed include How well do users see How well do users type How much education do users have What d
27. ing developed will have little exposure to the concept of an operating system concepts they will have to learn 16 TABLE 9 OPERATING SYSTEMS EXPERIENCE see note below Op Systems have used once per week PC DOS MS DOS 17 24 6 70 8 6 8 7 25 03 PRO DOS 1 1 4 4 2 1 1 4 4 2 UNIX 1 1 4 4 2 O VM 2 2 9 8 3 2 2 9 8 3 CTOS 1 1 4 4 2 1 1 4 4 2 Macintosh 4 5 8 16 7 2 2 9 8 3 NOS BE 4 5 8 16 7 4 5 8 16 7 MTS 2 2 9 8 3 1 1 4 4 2 MULTICS 1 1 4 4 2 1 1 4 4 2 other 5 7 2 20 8 2 2 9 8 3 who responded 24 who have not used computers 45 65 2 Sample 69 missing 53 The 17 people who have used PC DOS MS DOS represent 24 6 of the sample 69 who responded to question 14 51 of the people who resonded to question 14 did not respond to this question They represent 70 8 of the 24 people who responded to this question Since more than one choice was available percentages will not total 100 Participants were also asked to specify the computer applications they have used See Table 10 Chrysler CAD CAM word processing and games were the applications most often cited I7 TABLE 10 APPLICATIONS EXPERIENCE see note below Applications have used once per week Word Processing 26 25 5 45 6 7 6 9 12 3 Business Graphics 9 8 8 15 8 2 2 0 3 5 Spreadsheets 7 6 9 12 34 4 3 9
28. ity of Michigan Chrysler Center for Continuing Engineering Education Taylor 1987 What Do Users Do On The Job Table 5 shows the reported occupations of the survey respondents Most of them are either designers 25 artists sculptors 36 or studio engineers 19 Noteworthy is the category studio engineer a title that does not neatly map into one academic discipline and is not necessarily a title with which software developers would be familiar TABLE 5 OCCUPATION Designer 31 25 4 Technician 1 0 83 Artist sculptor 44 36 13 Mechanical engineer 2 1 63 Electrical computer engineer 1 0 83 Studio engineer 19 15 63 Other engineer 10 8 2 Other 14 11 5 Sample 122 missing 0 11 Table 6 shows the amount of education completed by people in each occupational category Most of the designers completed college 25 of the 31 but few of the artists sculptors have 9 out of 44 Surprisingly few of the engineers only 8 of the 32 have college degrees This does not fit the stereotype of an engineer TABLE 6 OCCUPATION VS EDUCATION Occupation Level of Formal Education High Tech Some College Grad TOTAL School School College School Designer 1 1 25 4 31 Technician 1 1 Artist 8 5 20 9 2 44 Sculptor Mechanical 1 1 2 Engineer Elec Computer 1 1 Engineer Studio I 5 7 5 1 19 Engineer Other Engr 7 3 10 Other 2 1 6 4 1 14 TOTAL 12 12 43 46 9 122 Sample 122 missing 0
29. izing 29 24 4 Data entry 15 12 6 Statistics 5 4 2 Calculations 13 10 9 Data base management 5 4 2 Programming 4 3 4 Prepare business graphics 4 3 4 Mechanical drawing design 16 13 4 Artistic drawing design rendering 5 4 2 Other 2 1 7 Manually Make clay models 46 38 7 Mechanical drawing design 43 36 1 Artistic drawing design rendering 31 26 13 Use a typewriter 6 5 0 Use a calculator adding machine 32 26 9 Other 12 10 1 Sample 119 missing 3 Related data collected in 1986 from a survey about the American auto industry addresses the issue of computer use D Andrea 1987 Executives were asked what percentage of their company s product design engineers operate from a microprocessor based workstation the median response was 40 When asked what percentage of product design in their company s engineering unit was performed with the aid of a computer the median response was 50 1 Based upon confidential data Office for the Study of Automotive Transportation 1986 DELPHI IV Forecast and Analysis of the U S Automotive Industry Through 1995 Ann Arbor Michigan The University of Michigan University of Michigan Transportation Research Institute 14 How Well Do Users Type Most people in the Product Design Office are not proficient typists Of those responding 12 reportedly cannot type 16 type with one finger 19 use two fingers 29 can type with more than 2 but less t
30. l education respondents have as a function of their discipline Noteworthy are the data for those who studied mechanical engineering 21 of those 22 do not have a college degree However 26 of the 35 who concentrated in industrial design have graduated from college a ae TABLE 2 AREA OF STUDY VS FORMAL EDUCATION Area Level of Formal Education of Study High Tech Some College Grad TOTAL School School College School Engineering 3 1 4 Mechanical 4 17 1 22 Civil 1 1 Automotive 1 1 Packaging 1 1 Business 1 1 Management 1 1 Marketing 1 1 2 Ind Mgmt 1 1 Fine Arts 2 4 1 7 Graphics 1 5 6 Sculpture I 1 2 Design Industrial 1 5 26 35 Automotive 1 2 3 Other Tech 4 1 5 Drafting 2 1 1 4 Other 1 1 1 3 TOTAL 2 8 40 41 8 99 Sample 99 missing 23 Only 37 9 of the respondents have recently attended any short courses or seminars The general subject matter of seminars attended is shown in Table 3 with the most frequent listing being communication type seminars Very few participants 3 of 115 have attended any type of computer course TABLE 3 SEMINARS ATTENDED see note below Seminar Type First Second Management 4 3 5 9 3 1 1 2 11 13 Communications 10 8 7 23 3 1 1 2 11 13 Design 3 2 6 7 0 1 1 2 11 13 Computers 2 1 7 4 7 1 1 2 11 13 Other 24 20 9 55 8 5 6 2
31. man cannonball 2 1 6 mechanical engineer 1 0 8 electrical computer engineer 10 8 2 other engineer gt what type 19 15 6 studio engineer 14 11 5 other Sample 122 missing 0 10 What is your job title 39 JOB TITLE tech manager 2 1 6 non tech manager 15 12 3 other manager 5 4 13 engineer 30 24 6 designer 23 18 9 sculptor 45 36 93 other 2 1 6 Sample 122 missing 0 How long have you been working in your current field mean 16 7 years min 1 max 38 std dev 10 8 Sample 122 missing 0 What tasks do you perform on your job check all that apply using a computer 61 3 73 6 4 3 4 24 4 12 6 29 15 5 13 10 9 3 4 3 4 3 4 13 4 4 16 5 2 1 7 5 0 4 23 4 2 4 23 manually 46 43 36 1 26 1 31 6 5 0 26 9 32 12 10 1 Sample 119 38 7 don t use a computer on my job word processing prepare spreadsheets digitizing data entry statistics calculations data base management programming prepare business graphics mechanical drawing design artistic drawing design rendering other s make clay models mechanical drawing design artistic drawing design rendering use a typewriter use a calculator adding machine other s missing 3 I1 Iz I3 36 How do you type check one 14 11 7 can t type go to question 1
32. most all had at least a high school education they had little experience with computers For example 61 do not EEN use a computer on the job and 37 5 had never used a computer Other useful pieces of information included candidate users occupations 36 artists sculptors 25 engineering 15 fine arts typing ability only 24 can touch type and vision almost half wear glasses almost 25 wear bifocals 17 Key Words 18 Distribution Statement User interfaces human factors ergonomics CAD usability usability engineering ease of use novice users 19 Security Clessif of this ropert D Security Classif of this pege 21 No of Poges 22 Price Unclassified Unclassified 43 TABLE OF CONTENTS PREFACE INTRODUCTION What Are the Key Human Factors Principles Where Do These Principles Fit into the Development Process What Do Developers Need to Know About Users TEST PLAN Survey Respondents Survey Contents Data Collection Procedure RESULTS AND DISCUSSION How Well Do Users See How Much Education Do Users Have What Do Users Do On The Job How Well Do Users Type What Computer Hardware and Software Are Users Familiar With CONCLUSIONS REFERENCES APPENDICES APPENDIX A SURVEY FORM APPENDIX B SUMMARY STATISTICS 10 14 14 19 21 24 31 PREFACE This report the first in a series describes the overall plan for developing a user interface to a CAD system and describes the candi
33. nciples and their application in the development process are described below What Are the Key Human Factors Principles The principles involved in designing a user friendly interface have long been assumed to be obvious so obvious that they were often not discussed That s changing especially for computer systems Gould and Lewis 1983 1984 1985 have been instrumental in causing that change To develop easy to use systems they recommend early and continual focus on users empirical measurement of usage and iterative design whereby the system is modified tested modified again tested again and the cycle is repeated Gould and Lewis 1985 p 300 What do these principles mean By early focus on users Gould and Lewis mean that interface developers should identify and understand all of the human characteristics in particular behavioral factors that may affect how users interact with the system being developed This information can be obtained through user surveys and by making direct contact with users through interviews The information should be obtained prior to the design phase To encourage direct contact Gould and Lewis suggest one or two users should be included on the development team In addition they also urge developers to study proposed users at work Data worth collecting include detailed descriptions of the tasks performed and task frequencies durations importance and so forth These data may be obtained fr
34. nt 24 6 of the sample 69 who responded to question 14 51 of the people who resonded to question 14 did not respond to this question They represent 70 8 of the 24 people who responded to this question Since more than one choice was availabe percentages will not total 100 40 Below is a list of computer applications In the left column check all those that you have used either at work or at home In the right column check all those that you use at least once per week Applications have used once per week see message below see message below word processing 26 25 5 45 6 7 6 9 12 33 business graphics 9 8 8 15 8 2 2 0 3 5 spreadsheets 7 6 9 12 3 4 3 9 7 0 artwork 12 11 8 21 5 5 4 9 8 8 statistics 5 4 9 8 8 2 2 0 3 5 data base mgmt 7 6 9 12 3 2 2 0 3 5 programming 11 10 8 19 3 5 4 9 8 85 Chrysler CADCAM 31 30 4 54 4 13 12 7 22 8 other CAD CAM 7 6 9 12 34 1 1 0 1 834 games 20 19 6 35 1 4 3 9 7 0 other 2 2 0 3 55 1 1 0 1 8 who responded 57 who have not used computers 45 44 13 Sample 102 missing 20 The 26 people who have done word processing represent 25 5 of the sample 102 that responded to question 14 18 people who resonded to question 14 did not respond to this question They represent 45 6 of the 57 people who responded to this question Since more than one choice was availa
35. o users do on the job What computer hardware and software are users familiar with TEST PLAN Survey Respondents The survey was distributed to all employees of the Chrysler Motors Product Design Office in Highland Park Michigan That department is responsible for styling Chrysler cars and trucks Of the approximately 240 people in the Department 132 responded Participation was voluntary Of those responding the data from 10 people were omitted from the sample Based on their job titles e g secretary operations analyst it was felt they would never use the new CAS system Survey Contents The survey was 7 pages long A copy of the complete survey is included in Appendix A The survey consisted of a cover page with an introduction and instructions and 6 pages of questions The 24 questions concerned basic biographical information and respondents education occupation and computer experience At the request of the Product Design Office age and sex data were not collected Typical questions were What is your visual acuity e g 20 20 What is the highest level of formal education you have completed What tasks do you perform on your job Do you usually look at the keyboard when you type How long have you been using computers Which pointing devices have you used Data Collection Procedure Surveys were distributed to design staff employees by their immediate supervisors Supervisors instructed their employees th
36. om casual observations of users online logging of user behavior or conventional time studies or activity samples The second major principle is that of empirical measurement of usage Objective user performance data such as the time and errors made when carrying out benchmark tasks and subjective measures such as ratings of difficulty of various activities should be collected These data should be analyzed for both prototype and working versions of the software Whenever possible decisions about interface design should be based upon quantitative information obtained from users To collect these data prototypes are needed early in the development process The third major principle is that of iterative design That is after each user test designers should modify the system according to the test results Many believe this is just fine tuning however experience suggests it is unlikely that a user interface will be designed correctly the first time Therefore the development schedule must allow for several iterations so that a user friendly interface can be developed While these principles might seem obvious the evidence suggests otherwise For example Gould and Lewis asked 447 IBM computer system developers to identify the key steps in developing and evaluating a system for end users While 62 said something about users only 40 said anything about empirical measurement and only 20 referred to iterative design It is clear
37. rity This has numerous implications First of all most potential users will not be familiar with the terminology and concepts commonly used Thus users will need training both in the specifics of the system being developed and in basic concepts e g what a file is what opening a file means what an operating system is etc Secondly although the favorite input device among computer users was a mouse most of those surveyed have never used a mouse This implies that some training in its use may be needed The results of this survey describe the Chrysler Design Office employees as moderately educated experienced at their current job relatively poor typists and for the most part unfamiliar with computers and application software What makes this report useful is not that summary statement but the statistics that support it To a large degree the significance of this report will only become apparent when detailed design of the interface is underway It is at this stage that alternative input devices screen formats etc must be analyzed The data collected by this survey which describe user capabilites and experience will assist in deciding among these alternatives 21 REFERENCES Andrea D 1987 personal communication Bennett J L 1984 Managing to Meet Usability Requirements in Bennett J Case D Sandelin J and Smith M eds Visual Display Terminals Usability and Health Concerns Englewood Cliffs NJ 1
38. s will affect their ability to read the screen comfortably Therefore text to be read should be located low in the visual field and be confined to a relatively small area Another alternative would be to provide Special reading glasses How much education do users have The overwhelming majority of users have at least a high school education Therefore material to be read instructions documentation commands etc should be written at a 12th grade reading level or below Although the range in education level in the survey sample is substantial it can be assumed that nearly all users will be able to read at this level How well do users type The data collected indicate that this group of potential users has relatively limited typing abilities This would indicate that in order to maintain efficiency users should do as little typing as possible Other means of interacting with the system should be provided Also it may be appropriate to improve the typing skills of those who cannot touch type What do users do on the job While these users have many job specific skills computer expertise is not one of them Well over half do not now use a computer on the job Thus these users are truly novices However it should be remembered that there are a few potential users who use computers extensively 20 What computer hardware and software are users familiar with Very few of those surveyed currently use a computer with any degree of regula
39. sample responding to specific choice third value in parentheses of responses to specific choice For questions where more than one choice is available percentages will not total 100 BIOGRAPHICAL INFORMATION 1 Are you check one 101 82 8 right handed 13 10 7 left handed 8 6 6 ambidextrous Sample 122 missing 0 2 Do you wear check all that apply 58 47 5 glasses 13 10 7 contacts 29 23 8 bifocals Sample 122 missing 0 3 What is your visual acuity e g 20 20 mean 20 24 min 20 10 max 20 60 std dev 8 9 Sample 73 missing 49 EDUCATIONAL INFORMATION 4 What is the highest level of formal education you have completed check one 12 9 8 high school 12 9 8 technical vocational school 43 35 2 some college 46 37 7 college 9 7 4 graduate school Sample 122 missing 0 33 Indicate special areas of study e g mechanical engineering industrial design graphic arts a aaa AREA OF STUDY FIRST SECOND THIRD engineering 4 4 0 1 3 1 O mechanical engrg 22 22 2 1 3 1 O civil engrg 1 1 0 O O electrical engrg 0 1 3 1 O materials engrg O O 1 9 13 automotive engrg 1 1 0 O O packaging engrg 1 1 03 O O architecture O 1 3 15 O 29 29 2 4 12 5 1 9 5 business 1 1 0 3 9 4 O management 1 1 0 1 3 1 O marketing 2 2 0 O 1 9 13 industrial Mgmt 1 1 0 O O advertising O 1 3 1 1 9 13 real estate O 1 3 1 O 5 5 1
40. se speech as a method of input Yes No THANK YOU FOR YOUR TIME 31 APPENDIX B SUMMARY STATISTICS HUMAN FACTORS DIVISION Ms Susan Adams and Dr Paul Green 313 764 4158 INTRODUCTION This survey is being conducted by the University of Michigan Transportation Research Institute for the Chrysler Corporation Chrysler is planning to implement a new Computer Aided Surfacing CAS system which will be used to design interior and exterior car surfaces The University is helping to develop the user interface for this system The purpose of this survey is to determine the background of potential users of this new system so that a user friendly interface can be developed Since you are a potential user we would like to customize the system to fit your background This survey will NOT be used to select the users of the CAS system Chrysler will be given only the combined data from those surveyed not individual responses Take your time and answer the following questions as completely as you can If you have any questions concerning this Survey please contact Susan Adams or Paul Green at the above phone number or call Mike Holmes at 956 2106 Please see that this survey is returned to Mike Holmes We appreciate your cooperation in this effort 32 122 people participated in this survey Sample 122 of missing responses first value of responses to specific choice second value in parentheses of
41. y job word processing prepare spreadsheets digitizing data entry statistics calculations data base management programming prepare business graphics e g pie charts histograms mechanical drawing design artistic drawing design rendering other s manually make clay models mechanical drawing design artistic drawing design rendering use a typewriter use a calculator adding machine other s EL T2 13 14 ioe 16 27 How do you type check one can t type go to question 16 one finger two fingers more than two fingers but less than ten fingers all ten fingers Do you usually look at the keyboard when you type check one yes sometimes for numbers and letters sometimes for numbers but not for letters no Do you type fast enough to be a secretary Yes NO COMPUTER SYSTEMS EXPERIENCE Have you ever used a computer Yes No gt do not answer questions 15 24 How long have you been using computers years Do you use a computer at home Yes NO 17 18 28 Below is a list of computer hardware In the left column check all those that you have used either at work or at home In the right column check all those that you use at least once per week have once used per week IBM PC or compatible Apollo LISP AI machine Control Data Tektronix Control Data Evans amp Sutherland Sun Apple II Macintosh Commodore 64 Cyber 205 Cray VAX MicroVAX

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