Brugergrænseflader til apparater BRGA

Presentation 7:

Users

2

Outline

• Recap: Cognitive HCI & Heuristics• Problem with Predictive Mehtods• Users• Context or lab• Available methods involving users

Recap:

Cognitive HCI & Heuristics

4

Until now we have looked at

•Cognitive HCI:•Theory & Methods•Modeling Use (models)•Mainly predictive methods

• GOMS/KLA/Fitts Law• Designers: CW

•Heuristics & Guidelines•Distilled experiences•Avoid common design pitfalls by following design principles: guidelines & heuristics•Method: Heuristic Evaluation

5

The problem with predictive methods & heuristics / guidelines

• Makes overall assumptions• May often be right (that’s why we use them)• May sometimes be inadequate

• Makes assumptions on behalf of the users• But we cannot really know if these holds to be true

• The problem: we cannot be sure that we are building the right product – only that we are building the product right

• The solution: consulting the users

Now we will look at users & context

7

The UsersFour important guidelines apply (Nielsen):

1. Remember that you are NOT your typical user• “The designer” is not a good user

2. Know your users• “Everyone” is not a user• “The Vice President” is rarely the user• “Marketing” is rarely the user• If you can’t find a user – then you’re in big trouble!

3. Users aren’t designers• It is your job to generate visions (prototypes, future workshops) and

to collect their feedback

4. Users aren’t all-knowing• Beware of users giving you wrong information – use & study several

8

The Context

• Original Cognitive HCI is not concerned with the context where the work is situated

• Focus is on the mapping between the user & the computer in an isolated setting

• This approach has various flaws

9

The “new wave” of HCI psychology

• Social Computing (born in the late 80’s)• Users are not isolated beings• They are part of a context – social & cultural • Not possible to isolate the work context completely in a lab

• Solution• Study the users at the work setting (field studies & interviews)• Integrate users in the development team

10

Social Computing Concepts

• Distributed Cognition

• Situated Action Theory

• Activity Theory

• Participatory Design (field studies & interviews)

• Prototyping

• XP: eXtreme Programming (and other Agile Methods)

11

Social Computing

• Distributed Cognition (Edward Hutchins 1991)• The need to study more than one user at a time (a work

setting …)• Builds on Cognition Psychology

• Situated Action Theory (Lucy Suchman 1987)• Complete opposite of Cognitive Psychology. “Action only

takes place due to the situated context (you can NEVER predict how a user might act …)”

• Activity Theory (Sussanne Bødker 1989) • ”All activities are driven by needs, mediated by one or more

instruments, and always affected by the context of the activity”

• Psychology of the Sovjet Union: Vygotsky, Leontjev

12

Activity Theory

Subject

Instrument

Object (goal of Activity)

Rules Community Division of labour

Figure: Engeström’s triangle illustrates an Activity, and all the elements influencing it

• None of the elements can be separated• Need to understand the entirety – the overall context• This can be done by field studies (preliminary) + checklist• Evaluation of UI’s at best carried out in work context

Methods:

Activity Checklist

Focus Shift Analysis

mediates

other tools available?

disturbing factors (phones ringing)?

competing goals?

need for externalization (to colleagues)?Asyncronous communication (colleagues around the globe)

Who will be using the technology?

access to the tools? PC in office – farmer in stable

13

Warning

• Not all user involvement needs to be in the work context as this might be expensive

• As always - cost/benefit• Different methods to apply involving users

14

Techniques for Observing and Listening to Users

• Field studies / Contextual Inquiry / Lab observations• Think Aloud: talk while doing the job• Talk Right After : debriefing after the job• Role Playing• Cueing recall with videotape (Focus Shift Analysis)• Focus groups & interviews• Mailed surveys• Others: Retrospective Testing, Coaching Method,

Constructive Interaction

15

Field studies / Contextual Inquiry

• Field studies (Nielsen: Observations) are undertaken to understand the users work context and enable the designer to discover possible user needs• Use before design (task analysis) or with working

products

• Usually video recording is employed as well as note taking. Do not interfere with the work

• Contextual Inquiry• As field studies, but ask fitting questions

16

Environment Analysis

• Where do people use your interface? Many variations:• An outdoor ATM in a cold location where people wear

gloves while using it (need huge buttons)

• On a combination cell phone/wireless browser, with a tiny display (need tiny fingers!)

• In a location where direct sun can hit your display, making it hard to read

• In an extremely noisy factory, where any sound you add would be impossible to understand

• Observe your users in their own setting

17

Cueing Recall with Video

• After getting written permissions, tape the user at work• This records the user interacting with others in a

normal work setting• Later, play the tape and have the user explain what

was going on• Bødker: Focus Shift Analysis

18

Interviews

• Good with one user• Very qualititaitve – less suited for quantitative• Unstructured interviews (open questions)• Structured interviews (closed questions)• Semi-structured• Record findings

• Notes

• Audio

• Video (may be too intrusive)

19

Focus groups

• Bring users together (6 or more) for discussions• May obtain valuable end-user input• Requires a skilled and experienced leader• One or two people may dominate• Some people may get into side conversations

20

Questionnaires

• Very difficult to write good questions• Choice of mail list can bias results• A return rate of 10% is extremely good; 1-2% is typical• May report on what people think they do, not what they

actually do• Quality of answers (spent time)• May be inexpensive

21

Think Aloud

• Psychological Test Method• Both lab & in situ• (Tognazzini, 1992): might be big controlled

lab experiments with video cameras – or cheap no nonsense studies

• “May be the single most valuable … method” (Nielsen, 1993)

• Makes the users mental model of the system clear to us – to close the gap to the system model

22

Think Aloud

• Samples of facilitating remarks:• “Could you tell me what options you are

considering?”• “Is anything in particular puzzling you?”• “What might you do next?”

• BUT: No feedback, positive or negative

• No answers or hints

• If users get stuck, have them go on

• Neutral demeanor at all times

• ”I’m not the designer”

23

Think Aloud Exercise (10 min.)

• Divide into groups of two’s• Turn off Bluetooth on both off your phones• Switch mobile phones• Task:

• Start with first participant:• Attempt to discover and pair with 6110 Navigator • Second participant simply observeres – no interaction• But do take notes !• Now switch – second participant perform task – but now

using Think Aloud• First participant is facilitator – only facilitating remarks

• Discuss with neighbour – which method works best?• Plenum: we will discuss the experiences

24

Talk Right After

• Sometimes talking while doing the work is not feasible or unsafe

25

Talk Right After

• Talking right after may be best alternative to thinking aloud

26

Role Playing

• Some things happen so infrequently that there is no way to observe the user

• Someone may be able to play the role of a user in that situation

27

Recruiting Users

• If product is in use, test with real current users:• Employees• Customers

• If it is a new product – test with potential users• Provide incentives:

• Coffee mugs, T-shirts, wine

• Not family or friends: they won’t be critical enough• Ethical aspects

• Conduct all test with the deepest respect for their well-being

• Users are only “novice” users the first time!• Do not waste your usability testing resources on basic

problems – make sure your product is ready for testing

28

Number of Test Users

• Nielsen: http://www.useit.com/alertbox/20000319.html

29

Common Pitfalls

• Reliability• Huge differences between test users

• Best user up to 10x efficient

• 25% users twice as fast as the slowest 25%

• Who is volunteering – the best or worst?

• May use standard statistical tests

• Number of test users will determine reliability

• Validity• Are we measuring something useful?

• Statistics won’t help here – only common sense and experience

30

Læringsmåls alignment

• Når kurset er færdigt forventes den studerende at kunne:• Definere og beskrive forskellige typer af

brugergrænseflader til apparater og computere

• Definere og beskrive gængse teorier, metoder og retningslinier indenfor menneske-maskin-interaktion og anvende disse til at lave en brugervenlig brugergrænseflade til et givet apparat

• Designe og konstruere brugergrænsefladesoftware til udvalgte typer af brugergrænseflader

Brugerne er måskeden vigtigste faktorat tage højde for vedInteraktionsdesignDer er en hel delteoridannelse omkring brugertyper og bruger-inddragelse. Endeligt erder en lang rækkemetoder.