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Chapter 4. Finding out about tasks and work. Terminology. GOAL : End result or objective. TASK : An activity that a person has to do to accomplish a goal. TASK. TASK. ACTION : A step towards completing a task. ACTION. ACTION. More on GTAs. Goals talk about the “what”
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Chapter 4 Finding out about tasks and work
Terminology GOAL: End result or objective TASK: An activity that a person has to do to accomplish a goal TASK TASK ACTION: A step towards completing a task ACTION ACTION
More on GTAs • Goals talk about the “what” • Tasks & actions talk about the “how” • Tasks have characteristics • Time consuming, require special materials • Actions often involve interacting with the machine in question • i.e. “press the Enter key”
Task Analysis • The process of examining the way in which people perform their tasks. • Done by interview, observation, or reading • Work flow analysis to see the “big picture” • Shows communication & coordination across a company • Job analysis to see what individual workers do • What each person is responsible for on more short term basis • Ask workers about current problems with the system • Observation can also be very helpful here • Note any artifacts(any object used to perform a task) and how often they are used, what they are used for • General rule – cover the 5 W’s
TA Techniques • 2 types: WHAT and HOW • WHAT • Task scenarios: a narrative description about use of the current system • Concrete use cases: a more generic description about use of the current system; often divided into a list of “user actions” and “system responses” • Essential use cases: high level abstraction; focuses on user intentions and future system responsibilities • Use scenario: similar to a task scenario, but describes the future system and is based on user requirements
TA Techniques • HOW • Focus on decisions and types of knowledge needed • Cognitive walkthrough: evaluates steps required for a task and tries to discern differences between the users’ point of view and the designers’ point of view • Four outputs -- work arounds, artifacts, scenarios & use cases, and cognitive walkthrough results
Mental Models • A model of the world in our heads that enables us to negotiate unfamiliar situations • Formed through experience, training, and instruction • Some characteristics: incomplete, unstable, parsimonious (see box 4.5) • Two types: structural and functional • Structural: how it works (representation in memory); context-free (easier to extend & integrate) • Functional: how to use it (procedural); context dependent (easier to use) • Can be useful in design, but very hard to capture as every individual’s mental model is different; most people are not aware of having a model
Environmental Considerations • Physical environment – lighting, temperature, noise, layout • Safety – protective gear, stress levels, distractions, pollution, hazards • Social environment – cooperation, interdependence, help & learning, deadlines • Organizational environment – mission/purpose, structural working factors (i.e. hours, dynamics, etc), attitudes, flexibility • User support – manuals, training, mentoring
Effects of Environment on Design • Noise – auditory tone for alerts may no be heard • Dusty environment – protective coverings for equipment might be necessary • Users wear thick gloves – input devices should consider this