Everyday Design and Discount Usability

Question 1

Affordances

Answer 1

are those properties of the object which give users clues as to how the device is used

Question 2

Discoverable affordance

Answer 2

can be easily found/discovered when interacting with the object and then interaction reveals other affordances

Question 3

Hidden affordance

Answer 3

automatic appliance
puzzle boxes
easter eggs

Question 4

Learnable affordance

Answer 4

feedback –> discovery

• glass breaks easily
• puzzle pieces

the more natural an affordance the easy it is to learn

Question 5

Mapping

Answer 5

ensuring a correlation between objects and the interface controlling them

mapping associates
a potential action with a
particular reaction

Question 6

Transfer effects

Answer 6

people transfer expectations from known objects to similar new ones
Previous experience conflicts with new situation :(
Previous experience applies to new situation :)

Question 7

what can mappings and affordances depend on

Answer 7

Experience
knowedge
culture

Question 8

relationships between affordances and constraints

Answer 8

constraints limit affordances

• helps user enter correct information
• restrict the field of possible actions

Question 9

Costs making up the cost of quantitative testing

Answer 9

administrative - many users, user incentives, hiring and training
Usability expert person hours - study design and execution, stats analysis
special equipment

Question 10

costs making up the cost of qualitative testing

Answer 10

admin - user compensation, travel and time
usability expert person hours - interviews, transcriptiom analysis
specialized equipment

Question 11

benefits of discount usability techniques

Answer 11

cheap - no special labs or equipment
fast - fewer tester involved
easy to use - taught within 2-4 hours

Question 12

Discount usability techniques examples

Answer 12

cog walkthroughs
heuristic eval
crowd sourcing
system usability scale

Question 13

Describe a cognitive walkthrough

Answer 13

detailed task with concrete goal
action sequences for completion of task

will the users know what to do
will they notice that correct action is available
will the user interpret the feedback correctly

what would cause problems and why

Question 14

Outcome of cog walkthrough

Answer 14

Each assessor prepares a list of issues
-When did it occur?
-What happened?
-Severity
Compile all reports into one
-Note issues that occur frequently (more severe)
-Prioritize the issues to be addressed

Question 15

Pros of heuristic evaluation

Answer 15

catch design flaws
no users required
performed by experts
easy and inexpensive

Question 16

cons of heuristic evaluation

Answer 16

more difficult than seems
will interface address user goals
not just a checklist

Question 17

how to conduct heuristic evaluation

Answer 17

Small set (3-5) of evaluators (experts) examine UI:
check compliance with heuristics
different evaluators find different problems
evaluators can communicate afterwards to aggregate findings
designers use violations to redesign/fix problems

Question 18

10 Usability Heuristics

Answer 18

visibility of system status
match between system and real world
user control and freedom
error prevention
aesthetic and minimalist design
consistency and standards
flexibility and efficiency of use
recognition rather than recall
help and documentation
helo users recognize, diagnose and recover from errors

Question 19

4 steps of heuristic evaluation

Answer 19

Pre-eval training
Evaluation
- two passes - get feel for flow and scope and then focus on specific elements
- produce list of problems (each evaluator)
Severity rating - rank issues
Debriefing

Question 20

Why have multiple evaluations

Answer 20

one person will never be able to find all the problems in an interface

Question 21

Severity rating scale meaning

Answer 21

0 - violates heuristic but not at all a usability issues
1 - cosmetic - only fix if there is time available
2 - minor usability issue- fixing should be given low priority
3 - Major usability issue: high priority
4 - usability catastrophe: imperative to fix this before release

Used to allocate resources
Estimates need for more usability efforts
Combine frequency, impact, and persistence
Should be calculated after all evaluations are in
Should be done independently by evaluators

Question 22

What happens during debriefing

Answer 22

General discussion with evaluation participants
Brainstorm improvements to address major problems
Development team rates difficulty of fixing problems
Minimize criticism

Question 23

pros and cons of heurisric evaluation

Answer 23

1-2 hours per evaluator
Findings are straightforward
May miss problems or find “false positives

Question 24

pros and cons of user testing

Answer 24

Days or weeks of working with users
Requires interpretation of actions
Far more accurate: takes real users and tasks into account

Question 25

key features of system usability scale

Answer 25

each item rated on 5 point likert scale
alternate between positive and negative questions
scoring - scale position vs reverse scale position
Interpret distributions not scores – convert list of scores to percentile distributions
Feels quantitative (because there’s numbers) but still subjective

Question 26

when to use system usability scale

Answer 26

• SUS is not diagnostic. That is, it does not tell you what makes a system usable or not.
• SUS scores are not percentages, despite returning a value between 0 and 100
• people’s subjective assessments may not be consistent with whether or not they were successful using a system.
• Is SUS only for English speakers? Translations must be done with care and validated.

Question 27

when and how to use quick and dirty techniques correctly and efficiently

Answer 27

• early design stages
• recognize its limitations
  Not necessarily as comprehensive
  80% or “good enough”

For a real usability evaluation, you may consider alternating or combining quick and dirty techniques with more comprehensive studies