Usability and HCI


John Alexis Guerra Gómez


Slides:http://johnguerra.co/lectures/webDevelopment_fall2019/10_Usability/

Class page:http://johnguerra.co/classes/webDevelopment_fall2019/

Readings discussion

  • questions?

Evaluation

  • Controlled Experiments involving users
  • Natural settings involving users
  • Any setting not involving users

Expert reviews

  • Design Experts
  • Visualization Experts
  • Usability Experts
  • Domain Experts

Types of expert reviews

  • Heuristic evaluation (golden rules)
  • Guidelines review
  • Consistency inspection
  • Cognitive walkthrough
  • Metaphors of human thinking
  • Formal usability inspection (courtroom style)
  • Accesibility inspection

8 golden rules of design

  • Strive for consistency
  • Cater for universal usability
  • Offer informative feedback
  • Design dialogs to yield closure
  • Prevent errors
  • Permit easy reversal of actions
  • Support internal locus of control
  • Reduce short-term memory load

Controlled Experiments

  • Experiments in the lab
  • Controlled confounding variables
  • Measure one or more quantitative variables
    • Usability testing
    • Living labs

What to measure?

  • Time to learn
  • Speed of performance
  • Rate of errors
  • Retention over time
  • Subject satisfaction

Usability Testing

Brighton Uni Usability Lab

Natural settings involving users

  • Observation
  • Interviews
  • Logging

Triangulation

Different researchers observe the same effect

Interviews

  • Unstructured
  • Structured
  • Semi-structured
  • Focus group
  • Telephone/Online interviews

Questionnaire

Like interviews but without the researcher present

Likert Scale

What do you think?

  • Strongly disagree
  • disagree
  • ok
  • agree
  • Strongly agree

More about likert scales

  • Can be 3, 5, 7 or more responses
  • Continuos or Discrete
  • Middle response is the balance

Observation

  • User's setting
  • Can be direct or indirect

Direct Observation in the field

Ethnography

Direct Observation in controlled environments

  • Think aloud techniques

Direct Observation: tracking users

  • Diaries
  • Interaction Logs and web analytics

MILCS

  • Multi-dimensional
  • In-depth
  • Long-term
  • sase studies

Focus groups

One researcher, many attendees

Prototyping

  • Low vs high fidelity?
  • read data
  • build scenarios, tell a story

Quatitative evaluation

http://yatani.jp/teaching/doku.php?id=hcistats:anova

References