HCC class lecture 15 comments John Canny 3/14/05

Administrivia

Activity Theory Developed primarily by Vygotsky’s student Leont’ev. Wertsch argues that Vygotsky took a similar notion of “activity,” as a given, but never developed it. “Activity” doesn’t translate well into English, plus it is influenced by general Marxist principles. So we’ll explore the ideas through several examples:

What is Activity? Activity is a sustained human behavior directed toward some “Object,” and using a stable set of “tools”. Activity is a sustained human behavior directed toward some “Object,” and using a stable set of “tools”. The “Object” is something like a motive, but it can be concrete. The “Object” is something like a motive, but it can be concrete. SubjectObject Tools

What is Activity? A product development is example Activity. The designers are the subject of the Activity. They use a set of tools which could include CAD Software, real models, analysis software, , text editors etc. The object(ive) of the Activity is to produce a product design.

What is Activity? The product design activity map looks like this: The product design activity map looks like this: Subject (designers) Object (product design) Tools (CAD, Sim. SW , Web, paper docs..)

What is Activity? The Activity perspective is different from the task perspective that has driven AI, HCI and CogSci. Activities are long-lived (weeks, months or years). There is not a goal that you reach, but an “object” that you evolve. Subject (designers) Object (product design) Tools (CAD, Sim. SW , Web, paper docs..)

What is Activity? In task analysis, we are interested in dynamics: the order of actions and the changes they produce. In Activity analysis we are most interested in things whose role in the Activity is constant. To represent a task, we might use a state chart or HMM. For an Activity we might use a data schema. Subject Object Tools

More Examples A research project is another example Activity. The researchers involved are the (group) subject. The set of tools will include research papers, lab equipment, analysis software, , text editors etc. The object is a slipperier concept. It might be a particular research paper. Or the validation of a hypothesis. Subject (researchers) Object (hypothesis) Tools (papers, eqpt, SW, ,…)

Example Marketing a product is a sub- or distinct Activity to product development. The Subject is the marketing staff. Tools include surveys, user studies, tradeshows, contacts,… The Object is brand development. Subject (Marketing staff) Object (Brand developmt.) Tools (Surveys, studies, tradeshows..)

Example Elder Care is another example activity. The family members and professional care-givers are the subject. The tools are medicines, home-cooked meals, mobility aids, games, cars, phone and ,… The object is the elder’s health and well-being. SubjectObject Tools

More Examples Taking a university course, or teaching one. Winning a legal case. Maintaining the health of a patient. Designing (and building) a building.

More Examples Writing a novel, or making a movie. Writing a song, symphony or opera. Playing a character, performing a song.

More Examples Parenting… Enjoying TV (watching, recording, buying DVDs),… Gardening Cooking

Activity hierarchy Activity Action Operation ?? Task analysis, task modeling KLM, GOMS, Epic Activity Theory concept HCI/AI model

Activity and Context Activity Theory is often described as a “Theory of Context”. But what does this mean? A good task-based UI provides “affordances” or actions that are “ready to hand” to support the task. An activity model provides the subject(s), tools and object that should be ready-to-hand for the activity. You can think of these as “cognitive affordances.”

Activity and Context For example, in discussing a product development, a designer might mention: – –“The budget” – –“John” – –“Last week’s meeting” – –“The model” – –“Testers” But each project member is probably part of several budgets, knows many people named “John”, goes to dozen’s of meetings a week, etc. What is going on?

Activity and Context The activity localizes all of the “tools” (documents, programs, meetings etc.) that all the group members have used down to a manageable sized set. The activity localizes all of the “tools” (documents, programs, meetings etc.) that all the group members have used down to a manageable sized set. John’s knowledge tools Alice’s knowledge tools Their project

Activity Theory as a Method Sylvia Scribner traced Vygotsky’s developmental method: Observation of current behavior in situ of a rudimentary behavior Reconstruction of the historical phases of the cultural evolution of this behavior Experimental production of the change from rudimentary to higher forms of behavior Observation of this change. Engestrom argues this is the natural method to be applied in Activity theory.

Discussion Topics T1: The best text analysis algorithms for a variety of tasks seem to use numerical (BOW or graphical models) of texts. Discuss what information these representations capture and why they might be effective.