HCI Foundations: Lab 01

Documenting Weeks 01 to 04: From Cognitive Psychology to GOMS

Course Progress Journal

A reflection on core HCI concepts as discussed in Dix et al.

Week 1: Human Memory & Foundations

We explored the limitations and techniques of human memory as mentioned in Dix et al. (Ch. 1).

  • Memory Techniques: Association of events and stories improves retention (p. 39).
  • Memory Flow: Information moves from Short-Term Memory (STM) to Long-Term Memory (LTM) via rehearsal.
  • HCI Definition: The intersection of Psychology, Design, and Computer Science.
  • Key Figure: John M. Carroll, the father of HCI.

Miller's Law: The average person can store 7 ± 2 chunks of information in their STM.

Summary of Week 2

  • UI and Logo Design: Exercises in creating the user interface and logos for common, well-known applications.
  • The Pyramid of Roles: A discussion on the hierarchy between Thinkers (at the top of the pyramid) and Developers (at the bottom).
  • Student Presentations: Peer review and presentation of Week 1 topics by students.
  • Human Process Model: Introduction to the Semantic Net by Card, Newell, and Moran, which provides an analogy between how computers and humans process information.
  • Memory Retention: Studying The Forgetting Curve and understanding how active rehearsal decreases the rate of forgetting.
    • Graph depicting Ebbinghaus's Forgetting Curve, showing retention percentage over time without rehearsal.
  • Image Formats: Identifying the differences between Vector and Raster graphics.
  • The Automatic Syringe Dose Calculator: A case study where the design shifted from a standard calculator interface to an increment/decrement counter based on user surveys, highlighting that design is highly dependent on the target user.

The Seven Stages of Norman’s Model

The cognitive steps a user takes when interacting with a system:

  1. Goal: What the user wants to achieve.
  2. Intention: The internal decision to act.
  3. Specification: Defining the specific actions needed.
  4. Execution: Performing the physical action.
  5. Perception: Seeing the state of the world/device.
  6. Interpretation: Understanding what was perceived.
  7. Evaluation: Checking if the goal was reached.

Week 3: Quiz

The Quiz helped with the revision of previous weeks' concepts, and the three questions on Norman’s Seven Stages were particularly insightful.

The Seven Stages:

  1. Goal (Forming the objective)
  2. Intention (The decision to act)
  3. Specification (Selecting specific actions)
  4. Execution (Physical performance)
  5. Perception (Observing the state of the world)
  6. Interpretation (Understanding the observation)
  7. Evaluation (Comparing result with the goal)

Applied Scenarios:

  • Toggle Switch:
  • Who Paid Problem:
  • Automatic Syringe Dose Problem:

Week 4: Shneiderman’s Rules & GOMS

A transition into formal interface guidelines and the GOMS predictive model.

Shneiderman’s 8 Golden Rules (p. 283):

  1. Strive for Consistency
  2. Enable Frequent Users to use shortcuts
  3. Offer Informative Feedback
  4. Design dialogues to yield closure
  5. Offer Easy error handling
  6. Permit easy reversal of Action
  7. Promote internal locus of control i.e user should feel in control
  8. Reduce Memory load

GOMS vs. Norman:

GOMS: Goals, Operators, Methods, Selection Rules. Unlike Norman, GOMS does not model Specify, Perceive, Interpret, or Evaluate.