05-440/05-640 Interaction Techniques (IxT) - Spring 2025

Credits:	12 units
Time:	Monday / Wednesday, 2:00pm – 3:20pm
Instructor:	Brad Myers (he/him)
Location:	WEH 5312
TA:	TBD
Office Hours:	TBD
Course URL:	http://www.cs.cmu.edu/~bam/uicourse/05440inter2025 or www.uicourse.org (temporarily)
Course Textbook:	Pick, Click, Flick! The Story of Interaction Techniques by Brad Myers, free for digital copy for CMU! See: www.ixtbook.com.

Description

Interaction techniques (IxTs) are the low-level reusable building blocks out of which user interfaces are constructed. Examples include physical buttons, menus, scrollbars, touchscreen gestures such as flicking, text entry on computers and touchscreens, game controllers, interactions in 3D and virtual/augmented reality, consumer electronic controls such as remote controls, interactions with conversational agents, and adaptations of all of these for people with disabilities. This course will use my new book, Pick, Click, Flick! The Story of Interaction Techniques, which is available for free digitally to CMU; see www.ixtbook.com.

We will start with a history of the invention and development of these techniques, discuss the various options used today, and continue on to the future with the latest research on interaction techniques presented at conferences such as ACM CHI and UIST. Appropriate design and evaluation methods for interaction techniques will also be covered. Guest lectures from inventors of interaction techniques are planned.

Students will have a choice for final projects that can focus on historical or novel interaction techniques. For example, one option will be to create a novel technique, perform a user study of it, and write a paper about the result, which may be suitable for conference submission. (Previously, a group inventing a new way to do text entry on a watch did get a publication!) Another option is to create a Wikipedia page about an inventor or interaction technique. Or you could investigate and write a paper or make a video about the history and various previous designs for widely used interaction techniques, possibly including an interview with the inventor(s).

Note!

This course is rarely offered, since Prof. Myers is now the department head (Director) of the HCII. It was last offered in 2022 (and before that in 2019, 2016, and 2014), so you should take it now!

What is an "Interaction Technique"?

Informally, "Interaction Techniques" are things like menus, scroll bars, text entry fields, typing on a smart-phone with an on-screen keyboard, gestural interfaces like flicking to scroll, etc. More formally, here are some definitions:

My definition:

An “interaction technique” starts when the user performs an action that causes a product to respond and includes the direct feedback from the product to the user. Interaction techniques are generally reusable across various applications.

Wikipedia' s definition:

An interaction technique, user interface technique or input technique is a combination of hardware and software elements that provides a way for computer users to accomplish a single task.

Foley & van Dam's, 1990 textbook's definition:

An interaction technique is a way of using a physical input/output device to perform a generic task in a human-computer dialogue.

Prerequisite Knowledge

Students must have taken at least some introductory HCI course, such as 05-391 / 05-891 DHCS; 05-410 / 05-610 UCRE; 05-430/05-630 PUI; 05-431/05-631 SSUI; 05-863 Intro HCI Tech Exec; or equivalent, so they will have knowledge about UX Methods. Preference will be given to students in the degree programs of the HCII (Undergrad Minor in HCI, BS in HCI, M-HCI, PhD-HCI). Students do not need to know how to program - we would especially like to invite students interested in the history of computation to enroll. (Note: if you have a focus on the history of technology, but no courses in HCI, we may be willing to make an exception to that requirement--email the professor.)

Course Relevance

Interaction techniques are involved in virtually every use of computers, so a tiny change in the way an interaction technique works can have an enormous impact on billions of users. Also, new interaction techniques are being invented all the time, some of which are adopted into everyday user interfaces. However, there are still needs for new interaction techniques, such as ways for people to better enter text onto a smartwatch or smartphone, or how to better select and manipulate objects in virtual reality, pointing to the need for continued innovation. Finally, interaction techniques can have an enormous monetary value for companies, since they can be patented and licensed.

This course will be useful for anyone interested in why we interact with electronics the way we do, and for designers creating the interaction techniques of tomorrow who need to know the options and constraints and appropriate evaluation methods, and also for UI developers and consumers who want to get the most out of their interaction techniques.

Course Goals

After taking this course, students will be able to:

Articulate design issues regarding interaction techniques.

Design a new interaction technique given a set of requirements and constraints.

Evaluate interaction techniques using the appropriate tests for performance and usability.

Describe the historical progression of the most important interaction techniques and the factors that impacted their evolution and eventual widespread adoption.

Assessment Structure

The course will have 4 homeworks, a final project, and two tests: a midterm and one at the end of the course. In class participation, including possible in-class quizzes will also count as part of the grade.

Learning Resources

The professor has written a new book (published March, 2024) called "Pick, Click, Flick! The Story of Interaction Techniques" based on the material from previous versions of this course, and the readings will all come from that. Original sources, such as conference papers or articles will also be listed on the schedule. These will be marked as required, recommended, or optional.

The schedule and homeworks for 2025 is not yet ready, but it will be similar to the schedule for 2022 (the last time this course was offered) and the homeworks for 2022, in case you want to see the details of how the course runs.

We will have guest speakers who have invented or impacted Interaction Techniques, as in previous years, but none have been confirmed for 2025 yet.

A list of all the previous years where this course has been offered, with their materials and guest lectures, is also available.

Extra Time Commitments

Assignments, readings and the project for this course are done outside of class, but should fit within typical expectations based on the number of units of credit.

Final Project Ideas

It is expected that everyone in the class will do a final project, probably in teams of 2 to 4 students. Here are some ideas for final projects:

Create or edit a Wikipedia page about an interaction technique or about an inventor of one, with appropriate citations:

Previous years' projects including new pages for David Canfield Smith and Norm Cox, the entire Pull-to-Refresh page, and the history section for scrollbars: http://en.wikipedia.org/wiki/Scrollbar, and some others.
I generally promise the guest speakers that we would do this for them!

Help with a conference paper submission about measuring scrolling speed and accuracy, using our new Scrolling Test.
Reimplement some of the old techniques (e.g., old scroll bars; Xerox Star method for text editing; etc.), and possibly do a user test to see if they were actually worse than current versions
- Maybe enter it into the "Interaction Technique Museum" - https://hci-museum.lri.fr/
Do a thorough analysis of the data the class collected for homeworks 1, 3 and/or 4.
Document, evaluate, analyze, and critique one or more existing interaction techniques with appropriate evidence
- Maybe compare it with alternatives with a user study
- Maybe prepare a chapter for the interaction-design.org encyclopedia about it
- Maybe update the All the Widgets video with changes in this interaction technique since 1990 (or create a new section)
Pick a new (or relatively new) hardware pointing device or text editing technique, and do a thorough analysis of it:
Pick a particular, important milestone design, and enumerate and describe all of the novel interaction techniques introduced in that system. For example, what interaction techniques were first introduced in the:
- Star
- Lisa
- Macintosh
- Windows 95
- iPhone
- Oculus
- HoloLens
- etc.
Interview an inventor of a particular interaction technique:

Most of them are still alive, and Professor Myers is personally acquainted with many of them.
Create a video, audio and/or paper report

Invent a new interaction technique
- Implement or prototype it
- Do a user study of the result
- Write a conference-style paper discussing the design issues and evaluation (and optionally submit it to an appropriate conference)
- See example from a previous year:
  - Elliot Lockerman, Shuobi Wu, Ariel Rao, Jarret Lin, Neil Bantoc, and Brad Myers. "Smartwatch Text Entry Using Five to Seven Physical Keys," 2017 IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC'17), October 11 –14, 2017, Raleigh, NC, pp. 291-295. local pdf.
Create a project of your own design, in consultation with the professor.

Nice (Anonymous) Comments from Last Time Offered (2022)

"One of the best courses that I have taken as a designer. Brad's curiosity and enthusiasm rubs off and loved how he distilled all his knowledge of interaction techniques in to simple frameworks in his textbook - it has potential to be a must read for every HCI practitioner and interaction designer."

"The best interaction design course I have ever taken. Professor Myers is so patient in answering our questions."

"Very interesting class with a clear requirements and assignments. I like the testing format, as the class is very information dense, and the final project was fun to do. The guest lectures were also very interesting."

"I really like this course! It's my favorite course in the Masters program so far. Thank you professor Myers!"

"I learned everything I expected from this course, it even brought me more that is [beyond] my expectations. I appreciate the opportunity I luckily had to take this course. ... Overall, this course is the best course I took this semester."

"The structure provided for the paper assignments is very helpful for writing papers for the class and beyond."

"[My favorite part was] the breadth of the technique introductions, and also the final project is pretty interesting."

"Professor knows a lot and is enthusiastic about the content."

"This course made me think a lot about things that I would have otherwise glossed over. It also made me excited to work on creating my own interaction techniques."

"Learning about new interaction techniques was very interesting."

"I would recommend this course."

"[This course] is a great introduction to UX designers."

"Thank you for a great semester! I appreciate how the class prepared us for evaluating interaction techniques as well as writing academic papers."