identifying Needs and Establishing Requirements

identifying Needs and Establishing Requirements

1. WHAT, HOW, WHY?

   • WHAT ARE WE TRYING TO ACHIEVE?
     • Identifying needs
       • undertand the users, and their context of work, so that the system under development can suppot them in achieving their goals
       • From the needs identified, a set of stable requirements that form a sound basis to move forward into thinking about design
   • HOW CAN WE ACHIEVE THIS?
     • These activities progress in a sequential manner, the activities influence one another as the process iterates
   • WHY BOTHER?
     • The implications for both producer and customer are serious:
       • Anxiety and frustration
       • Lost revenue
       • Loss of customer confidence
   • WHY ESTABLISH REQUIREMENTS?

2. KINDS OF REQUIREMENTS

   • Functional Requirements
     • what the system should do
   • Non-functional Requirements
     • what constraints there are on the system and its development
   • Environmental Requirements
     • circumstances in which the interactive product will be expected to operate
       • Physical Environment
         • How much lighting, noise, and dust is expected in the operational environment
       • social environment
         • Such as collaboration and coordination, need to be explored in the context of the current development
       • organizational environment
         • How good is user support likely to be, how easily can it be obtained
       • technical environment
         • What technologies will the product run on or need to be compatible
   • User requirements
     • Capture the characteristics of the intended user group
   • usability requirements
     • Capture the usability goals and associated measures for a particular product

3. DATA GATHERING

   • TECHNIQUES
     • QUESTIONNARIES
     • INTERVIEWS
     • FOCUS GROUPS AND WORKSHOPS
     • Naturalistic Observation
     • Studying Documentation
   • Chosing Between techniques
     • Data Gathering diffe
       • The knowledge the analyst must hqye about basic cognitive processes
       • The amount of time they take and the level of detail and risk associated with the findings
     • 3 scales classificaction
       • Is the task a set of sequential steps or is it a rapidly overlapping series of subtasks?
       • Does the task involve high information content with complex visual displays to be interpreted, or low information content where simple signals are sufficient to alert the user?
       • Is the task intended to be performed by a layman without much training or by a practitioner skilled in the task domain?
   • Some Basic Data-gathering Guidelines
     • Focus on identifying the stakeholders' needs
     • takeholders' needs Involve all the stakeholder groups
     • Involving only one representative from each stakeholder group is not enough, especially if the group is large
     • Support the data-gathering sessions with suitable props, such as task descriptions and prototypes if available
     • use a combination fo data gathering techniques
     • Run a pilot session if possible to ensure that your data-gathering session is likely to go as planned
     • In an ideal world, you would understand what you are looking for and what kinds of analysis you want to do, and design the data-capture exercise to collect the data you want
     • How you record the data during a face-to-face data-gathering session is just as important as the technique(s) you use

4. TASK DESCRIPTION

   • Scenarios
     • It describes human activities or tasks in a story that allows exploration and discussion of contexts, needs, and requirements
   • use cases
     • Use cases also focus on user goals, but the emphasis here is on a user-system interaction rather than the user's task itself
   • essential use cases
     • Essential use cases were developed by Constantine and Lockwood (1999) to combat what they see as the limitations of both scenarios and use cases as described above

5. TASK ANALYSIS

   • is an umbrella term that covers techniques for investigating cognitive processes and physical actions, at a high level of abstraction and in minute detail
     • Hierarchical Task Analysis (HTA)
       • It involves breaking a task down into subtasks and then into sub-subtasks and so on

6. ANDREA NAVARRO 1196414

   • Preece, Rogers and Sharp;"Interaction design human computer inteaction", John Wiley & sons, Inc, 2002

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