Building Models

1
Building Models

• Part 1 Models good for defining system and user
  requirements
• Affinity diagrams
• Flow model
• Cultural model
• Sequence model
• Physical model
• Artifact model
• Source
• H. Beyer and K. Holtzblatt (1999), Contextual
  Design A Customer-Centered Approach to Systems
  Designs. San Francisco, CA Morgan Kaufmann.
• Note for more details on the following example,
  you should visit the InContext website at
  www.incent.com and follow the CDTools link to
  Resources and then Shopping Data Browser (on
  the right under Example Data.)

2
Affinity Diagram

• Use the Post-It notes to record insights and
  quotes from your observations and interviews.
• One phrase or quote per note.
• Write big enough for all to see.
• Post the notes on the wall.
• Walk the wall and rearrange the notes into like
  categories.
• When everyone is agreed on the categories, give
  each category a meaningful name and summarize the
  findings.
• Use the affinity diagram to generate design
  ideas, identify requirements, and inform other
  models.

3
Affinity Diagram
4
Flow Model

• Draw the primary user of the system in the center
  of the page.
• Use Post-It notes to add other users, people,
  roles, and physical objects as needed to define
  flows of work and information.
• Use annotated lines and arrows to indicate flows
  of information or work.
• Indicate opportunities for breakdowns in
  communications or work flow.
• Use the model to add to or refine requirements,
  define key interactions, and identify
  communication modes and methods.

5
Flow Model
6
Flow Model Detail
7
Cultural Model

• Draw a circle representing the primary user in
  center.
• Draw overlapping and concentric circles
  representing other entities that affect the
  primary user.
• Draw arrows indicating influences, constraints,
  and expectations.
• Identify individual and pervasive values that
  affect how the user will approach the task.
• Use the model to define subtleties that should
  affect system design.

8
Cultural Model
9
Sequence Model

• Define specific steps the user goes through to
  accomplish the task.
• Identify strategies and decision points.
• Identify breakdowns that make the task difficult
  to complete.
• Where appropriate, identify options and
  alternative strategies.
• Use the model to further define requirements,
  identify design opportunities, and begin to
  define potential interaction methods.

10
Sequence Model
11
Physical Model

• Diagram in detail the physical space in which the
  task is performed.
• Identify both official and unofficial
  designation of locations.
• Identify paths taken through the space during
  task performance.
• Define how users use the space to accomplish the
  task.
• Identify breakdowns where the physical space
  inhibits task performance.
• Use the model to develop system design
  requirements and opportunities.

12
Physical Model
13
Artifact Model

• Draw or diagram the artifacts used to accomplish
  the task.
• Specify the users intent in using the artifact.
• If necessary, identify variants of the artifacts.
• Identify potential breakdowns where the artifact
  inhibits task performance.
• Use the model to define user requirements and
  identify potential design directions.

14
Artifact Model
15
Building Models

• Part 2 Models good for defining interaction
• HTA
• GOMS
• OFM

16
Example HTA of ____________
17
Example OFM of _____________