Human Computer Interaction:

Mick McQuaid


Week TWO


  • Q and A from last time
  • Feedback from TA
  • In class presentations
  • Groups
  • Perception
  • Readings
  • Framer tutorial

Q and A from last time

Other methods

Q: I’m curious to see if we’ll learn about methods (not waterfall and agile) that are more effective for designers.

A: My view is that the iterative model (design, prototype, evaluate) is the most effective for designers. That’s the main method I like to teach because of its effectiveness. I also like to teach contextual design, which is (again in my opinion) the most effective toolset for designers.

Mental models

Q: “I have questions about mental models. Are they created naturally or do we create them with how we design technology? I know we will be going over psychology next, which may answer my question.

A: There are several definitions of the term mental model. The most prevalent definition holds that they are created naturally but can be influenced. A related term, conceptual model is used by Don Norman to illustrate how we can influence them in a positive way.

Accessibility and Ethnography

Q: I would like to know more about accessibility guidelines and ethnographic research in the context of user research and design.

A: I have a series of accessibility slides on my website at

You can look at those for an intro. If you look at the syllabus, you’ll see we don’t explicitly address accessibility or ethnographic research! I consider those important areas and will lobby Jacek to make them standard in a future semester.

More on ethnography

Ethnographic research is not used a lot in user research except in exotic fields like software intended to be used by physicians. For another class, I have some Youtube videos on ethnographic research because it is important in academic research on users (as opposed to industrial research). Those videos are at

They are not up to date with my thinking because I made them three years ago, but they will get you started.

Waterfall problem

Q: Even when there are valid proofs out there where the waterfall model is not an effective model, why are companies even today which are considered giants still follow the same model?

A: Money! Accountants rule many companies!


Q: How is HCI affected by AI?

A: Big question! It’s being affected in very many ways. I can hardly go to a talk on HCI without hearing ChatGPT being mentioned, for instance. I urge you to follow Hacker News discussions on AI, particularly large language models and image recognition, to begin to appreciate what’s going on right now that affects HCI. It really deserves its own course.

Unclear question

Q: How being a new to this HCI can I cope up with the preset and foundation clear in UX?

A: I don’t understand this question. Can you rephrase it at the end of today’s class (or even during class)?

Best practices

Q: What are the best practices for student of HCI other than readings?

A: My personal opinion is that passion projects are the most important things that HCI students do. These are UX projects where you notice a gap or problem that interests you and design a solution. You describe it on your portfolio site and you tell friends and recruiters about it to get feedback and refine it.

Feedback from TA

I’ve received some excellent feedback from the TA, both things that you’ve said and things that previous HCI students have said

  • You don’t want me to use the other instructor’s slides
  • The other instructor didn’t dwell too much on slides in previous course iterations
  • Previous students didn’t have time to do all the readings (there are strategies for this)
  • You’re hoping for more hands-on work and less lecture

In class presentations

Few people signed up for in class presentations and those who did signed up for more than one. Let’s straighten this out right now.


Are you all in groups now? Are you satisfied with your groups? Let’s make sure you’re on track right now. (Vaishnavi will ask you to sit with your groups in the second part of the class.)


Human Capabilities

  • What are our limits?
  • What are we on average?
  • What state are we in?

We can think about human capabilities from different perspectives. Can you think of others besides the list above?

Limits, averages, and states

What can you say about the previous list? For example, limits might include the limits of what a person can see or remember. The average might include what “most” people can see and remember, whatever “most” means. The state we are in might be bright sunlight or a loud nightclub or sitting in front of a computer in a dark room, all of which affect our limits temporarily.

Some limits

  • Magical number seven, from Miller (1956)
  • Resolving power of the human eye in lines per inch at distance
  • Color blindness


Details of chunking

The preceding list shows several common limits you might need to be aware of when designing digital artifacts. Miller (1956) found that people chunked items in short term memory into groups of seven, plus or minus two, as shown in the previous frame. That might suggest a limit for what you ask people to remember.

Jobs focused public attention on resolving power

A typical test for color blindness

Some findings of Gestalt psychology, 1927

A view of Gestalt principles

More on Gestalt principles

An example of Colorbrewer usage

You don’t notice the gorilla when counting

An influential and controversial book

Being watched by a picture influences you

Two systems controlling you

Causes and consequences of cognitive ease

Critique of Kahneman

The common critique of Kahneman is that the experiments can’t be replicated, in particular much of the research on priming. For example, a blog post at replication index summarizes some of the critiques.

An example of an optical illusion

Jacek’s perception slides

〈pause for Jacek’s slides〉


Readings last week included Hartson and Pyla (2019): Ch 1, 2, 4 and Norman (2013): Ch 1. These are pretty serious readings and you need to carve out time to devote to them. In addition, the readings in future weeks have to be done before class, not after. We’re only saving these readings for after class because it’s the first week.

Readings this week include Johnson (2020): Ch 1–5


none due this week (but you could get a head start!)


Hartson, Rex, and Pardha Pyla. 2019. The UX Book, 2nd Edition. Cambridge, MA: Morgan Kaufman.
Johnson, Jeff. 2020. Designing with the Mind in Mind, 3rd Edition. Cambridge, MA: Morgan Kaufman.
Miller, George A. 1956. “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information.” The Psychological Review 63: 81–97.
Norman, Donald A. 2013. The Design of Everyday Things, 2nd Edition. Basic Books.
Pohl, Rüdiger F., ed. 2004. Cognitive Illusions: A Handbook on Fallacies and Biases in Thinking, Judgement and Memory. New York: Psychology Press.
Wertheimer, Max. 1938. “Laws of Organization in Perceptual Forms.”



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