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 ACTION: A step towards completing a task ACTION TASK

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

Questions???