L5: Human Error & Feedback

Question 1

A “slip” is an error of…

Answer 1

Execution

Question 2

Lapses is an error of…

Answer 2

Lapses typically occur while the user is performing their actions, and they either forget a step or lose track of what they are doing.

Question 3

How should we treat user input?

Answer 3

Be flexible; allow users to make common mistakes and report errors only when necessary.

Question 4

What are the three characteristics of feedback?

Answer 4

1. Timing: Feedback should be presented as soon as an event has occurred.
2. Location: Feedback should be provided near to the source of an event. Helps guide the users in making modifications
3. Meaning: Users must be able to understand and act of feedback

Question 5

Which is NOT TRUE? For error messages, pop-up message boxes are…

a. Ideal and should be used wherever possible
b. Distracting and should be avoided
c. Particularly confusing when multiple windows are open

Answer 5

a. ideal and should be used wherever possible

Question 6

Why is the appropriate placement of error messages so important? Give an example.

Answer 6

It is very important to place error messages appropriately because it’ll help users move on to completing their goals after making their errors. When users make errors, they need to understand what mistakes they made so they can correct them with little effort to move on.

An example of appropriate placement of error messages is displaying error messages inline with the inaccurate fields that the users made an error on. It allows users to correct their mistakes faster and easier.

Question 7

What are the three levels of performance of human error?

Answer 7

1. Novel problems: knowledge
2. Intermediate: Rule-based
3. Routine problems: Skill-based

Question 8

If action is irreversible

Answer 8

display distinctive confirmation dialog

Question 9

If action is time-consuming

Answer 9

provide cancel during processing

Question 10

If action is part of a multi-step process

Answer 10

Provide next, black and cancel

Question 11

If action is complex…

Answer 11

Display preview feedback and help

Question 12

If action has failed…

Answer 12

give appropriate feedback or provide error recovery if high impact

Question 13

Who needs to know about errors?

Answer 13

Developer or organization: log it and automatically notify (don’t treat users as messengers). Users: only as a last resort and if users can take meaningful actions

Question 14

When engaging users, our aim should be to achieve a sense of

Answer 14

flow

Question 15

What is flow?

Answer 15

1. Complete involvement of the ‘actor’
2. No conscious intervention (a ‘transparent’ interface)
3. Appropriate pacing of activity
4. The appropriate degree of difficulty

Question 16

What is information foraging theory

Answer 16

The scent information

Question 17

Coupled with the flow, we need to make sure that users feel

Answer 17

their effort is rewarded and they are getting closer to their goal

Question 18

Error messages should be a last resort (prevention is better than cure): First, consider:

Answer 18

1. Appropriate controls to restrict users’ choice to valid combinations
2. Scripting to allow web page controls to behave dynamically (disabling inappropriate choices)
3. Flexible and intelligent processing of user-supplied data (dates, credit card numbers and similar)
   4.

Question 19

Why should you avoid pop-up message boxes?

Answer 19

They interrupt flow and can be confusing when multiple windows are open

Question 20

Good error messages should:

Answer 20

1. Inform clearly and explicitly
2. Provide a constructive solution (no dead0ends: “this is what’s happened and this is what you can do about”)
3. Be non-accusatory(not “you did something wrong”)
   4/ Not pass the buck (avoid “this was my problem, no it’s yours” mentality”)