CCT 333: Imagining the Audience in a Wired WorldClass 8: Understanding Interaction in

Complex Environments

Complexity and Interaction

• What technologies may get more complex to use when more people are involved?

• Designing for lots of simultaneous users can be daunting

• New technologies and contexts can also be difficult

Ergonomics

• Why pay attention to ergonomics?• Inclusive design (design not just for average,

but all?)• Efficient interaction (Fitts’ law)• Selling point (ergonomic design in consumer

products)• Legal requirements (carpal tunnel questions)

Designing for ergonomics

• Prototype testing (virtual or real)

• Response time

• Environmental simulation

• Power and load characteristics

• Acute and chronic use (some effects only show up over repeated use)

Distributed Cognition

• People interact with other people using other tools to realize activity

• Communication and coordination becomes essential - interaction challenges?

Internal/External/Shared

• Internal representations - individual mental models of reality

• External representations - anything outside individual that guides activity (e.g., layout, notes, diagrams, etc.)

• Shared representations - individuals come together over external representations to create shared understanding (or confusion…)

Plans and Situated Actions

• Treats user interaction as a set of defined plans

• Plans in context - often contingent and less cut and dry than expected

• Humans don’t crash when plans fail - we adapt, create new plans on the fly

Hierarchical Task Analysis

• Flowcharting interaction patterns - order of actions, decisions made

• Arbitrary and acontextual - how things should be done, not necessarily how they are - but a good first step nonetheless

Start

Process

?

End

Input

Process

Y

N

Cognitive Walkthrough

• Going through the task analysis as actually performed in context

• Do users actually perform tasks as set out in plans?

• If not, what problems do they have?• “think aloud” strategy - get users to vocalize

their decision patterns and their confusion

Activity Theory

• Represents complexity of interaction among subjects, objects, artefacts and cultural expectations

• As a theory, can be hard to use in practice - but also quite powerful

Artefact

Subject Object

Praxis Community Division ofLabour

Nodes in Activity Triangle

• Subject - people

• Object - goal, task

• Artefact - tools, technologies

• Community - others affected by activity

• Division of Labour - Power relations

• Praxis - norms governing activity

Contradictions

• Primary - conflict at node (e.g., two people, different notions)

• Secondary - conflict between nodes (e.g., power relations frustrating action)

• Tertiary - conflicts when activites are redesigned (e.g., new process conflicts with models used in old)

• Quarternary - conflicts between simultaneous activities (e.g., one action contradicts another)

Example: CVEs

• Collaborative virtual environments - VR which embodies user in virtual space

• Affords interaction with other embodied users in real time

• Second Life example

CVEs in Conferences

• Interesting way to bridge distance gaps

• Time gaps a problem

• Orientation issues in virtual world - people talking to walls, etc. (and why it doesn’t matter)

• Confusing spaces and avatars - fantastic displays but for what purpose?

Activity Theory Analysis

• Subjects - conference attendees• Object - engage in collaboration, talk• Artefacts - virtual conference environment,

posters, websites, etc.• Community - attendees, lurkers• Division of Labour - who is/is not allowed to

talk at any given time, access restrictions• Praxis - expectations of conference

environment, turn-taking, etc.

Task Analysis

• Difficult to analyze as whole - there’s no “right” way to attend a conference

• Specific elements can be analyzed though - e.g., conference registration and payment

Next week

• Scenarios and requirements

• Should be on the verge of doing your user studies now - with results (at least preliminary) for next week so requirements can be determined