HCI 2.1 class notes (https://classroom.udacity.com/courses/ud400/lessons/9044917867/concepts/91374998190923)

Processor:

  • take input in, push output out
  • interface must fit within known human limits (senses, memory, physical capability)
  • evaluated with quantitative experiments

Predictor:

  • accounts for human’s knowledge, experience, expectations, thought process
  • they need to be able to predict what will happen as a result of actions they take
  • must fit with their knowledge, what they already know
  • evaluated by qualitative studies (eg ex situ aka controlled environment)
  • ex situ examples:
    • task analyses to see where users are spending their time
    • cognitive walkthrus to understand user thought process
  • but still focuses on one user, one task

HCI 2.2 feedback cycles https://classroom.udacity.com/courses/ud400/lessons/9129419879/concepts/91335799750923

  • gulf of execution: distance between user’s goals and the actions required to realize those goals
  • gulf of evaluation: distance between effects of those actions and the user’s understanding of the results

Execution

steps

  • identify intentions (may misunderstand what they want from the system)
  • identify actions (need to know what to do)
  • execute in interface

5 tips

  • make functions discoverable
  • let user mess around safely (avoid irreversible buttons)
  • be consistent with other tools (ctrl c + v, diskette icon for save)
  • know your user (novice vs action)
  • feedforward - hints on what user might want to do (as opposed to feedback - response to user action)

Evaluation

Evaluate new state of system

  • actual interface output
  • interpretation (can user interpret?)
  • evaluation (can user use this info to evaluate whether their goal was achieved)

5 tips

  • give feedback constantly
  • give feedback immediately
  • match feedback to the action
  • vary your feedback
  • leverage direct manipulation

Norman’s Feedback cycle

Execution (Goal -> world) : how easily can you determine function of device? (what do i want to do)

- [Reflective/Metacognition] plan: How easily can you tell what actions are possibile? (what are the alternatives)
- [Behavioral/Deliberation] specify: How easily can you determine mapping from intent to movement? (what can i do)
- [Visceral/Reaction] perform: How easily can you perform physical movement? (how do i do it)

Evaluation (World -> Goal)

- [Reflective/Metacognition] compare: How easily can you tell what state the system is in (what happened?)
- [Behavioral/Deliberation] interpret: How easily can you tell if the system is in desired state? (what does it mean?)
- [Visceral/Reaction] perceive: how easily can user compare what is happening to what they wanted to happen (is this ok?)

Assignment P1 (Fall 2018)

Answer the following prompt in a maximum of 8 pages (excluding references) in JDF format. Any content beyond 8 pages will not be considered for a grade. 8 pages is a maximum, not a target; our recommended per-section lengths intentionally add to less than 8 pages to leave you room to decide where to delve into more detail. This length is intentionally set expecting that your submission will include diagrams, drawings, pictures, etc. These should be incorporated into the body of the paper unless specifically required to be included in an appendix.

If you would like to include additional information beyond the word limit, you may include it in clearly-marked appendices. These materials will not be used in grading your assignment, but they may help you get better feedback from your classmates and grader.

Question 1 (from Lesson 2.1): ~1.5 pages

As a Georgia Tech OMSCS student, you likely regularly use Canvas, Canvas, Piazza, Udacity, and other tools. Select one of these interfaces (or one piece of one interface).

First, discuss that interface from the perspective of the processor model of the user. The processor model is concerned with objective, measurable outcomes, so note the efficiency with which you can accomplish different tasks.

Second, discuss that interface from the perspective of the predictor model of the user. The predictor model is concerned with what you predict will be the outcome of your action, and whether you can interpret whether the outcome matched your prediction, so focus on how the user perceives and interprets what they should do and whether it was successful.

Finally, compare the insights you gained from each of the previous discussions. What sorts of improvements would the processor model suggest, and how do they differ from the sorts of improvements that the predictor model would suggest?

Hint: Remember, the predictor model is not about interfaces predicting users’ intentions. The predictor model is about paying attention to what the user predicts the outcome of their action will be, and how they will interpret what they see after their action is complete.

Question 2 (from Lesson 2.1): ~1.5 pages

When we take the participant view of the user, we look at the entire context surrounding their activity. However, some interfaces are designed for activities that exist in different contexts.

First, select one activity you perform with a computer interface in multiple contexts. For example, you might use a text messaging app while walking down the street, sitting at your desk, eating a meal, or driving your car (though hopefully not!). You shouldn’t select text messaging: select some activity that is not used as an example in this question prompt.

Then, discuss how the different contexts surrounding the app add different constraints or challenges to using the app. For example, with a text messaging app, your cognitive resources are more divided eating or driving, and your physical precision is less reliable while walking.

Finally, describe how the design of the interface might be altered to perform differently depending on your context to overcome those constraints. You