Chapter+Eleven

=Chapter 9 – Requirements= //9.1 What are requirements?// - Something a product must do or quality it must have - Take current design and use requirements to design new system - Additional requirements emerge during the design process - //Requirements specification//: Formal document which contains requirements - //2 types// o Functional § What the system must do o  Non-functional § Quality the system must have § Concern the way the functionality operates § Image, usability, performance, maintainability, security, cultural acceptability and legal restrictions

Prioritizing requirements - Review with users and clients and modified when necessary - Use MoSCoW rules for categorizing o Must have - fundamental o Should have – essential if more time were available. System is usable without o Could have – Lesser importance o Want to have but Won’t have this time round – Can wait until a later development - MoSCoW rules are part of DSDM (Dynamic Systems Development) method

//9.2 Participative design and requirements// - Requirements gathering - Requirements generation - Requirements elicitation - Requirements engineering - Involves using variety of techniques to understand and analyze someone’s needs and aspirations - Maintain human centered approach to design

//9.3 Interviews// - Most effective ways of gathering information about what people want - Structured interview o Uses questions which are developed beforehand o People are limited to replies <span style="font-family: 'Arial','sans-serif';">- Semi-structured interview o Pre-prepared questions sometimes o Can reword and appropriate where necessary o Start at broad level and get into more detail as interview progresses <span style="font-family: 'Arial','sans-serif';">- Unstructured interviews o Use when very little background information is available o No preset questions or topics beyond general subject

Stories, scenarios and early prototyping in interviewing <span style="font-family: 'Arial','sans-serif';">- Aids to understanding <span style="font-family: 'Arial','sans-serif';">- Prevent abstract thinking <span style="font-family: 'Arial','sans-serif';">- Identify circumstances the new design will have to entail <span style="font-family: 'Arial','sans-serif';">- Prototypes are used to embody scenarios in possible technology <span style="font-family: 'Arial','sans-serif';">- Analyst and user ‘walk through’ scenario while analyst probes for comments or suggestions

Think aloud commentaries <span style="font-family: 'Arial','sans-serif';">- Low-level detail about current technology <span style="font-family: 'Arial','sans-serif';">- Include internal cognitive processes <span style="font-family: 'Arial','sans-serif';">- Useful in determining problems <span style="font-family: 'Arial','sans-serif';">- Interferes with process you are studying <span style="font-family: 'Arial','sans-serif';">- Not all cognitive processes can be accessed by conscious mind

//9.4 Practical considerations in interviewing// Preparation <span style="font-family: 'Arial','sans-serif';">- Get to know background <span style="font-family: 'Arial','sans-serif';">- Understand the language

Keeping track of the interview <span style="font-family: 'Arial','sans-serif';">- Pair of interviewers is most effective <span style="font-family: 'Arial','sans-serif';">- Audio or video tape is convenient but time consuming afterwards <span style="font-family: 'Arial','sans-serif';">- Note-taking is helpful – create timestamps

Telling stories <span style="font-family: 'Arial','sans-serif';">- Can be misleading <span style="font-family: 'Arial','sans-serif';">- Disproportionate emphasis

Reflection and exploration <span style="font-family: 'Arial','sans-serif';">- Reflecting back on the interview helps understanding <span style="font-family: 'Arial','sans-serif';">- Have interviewee summarize at the end <span style="font-family: 'Arial','sans-serif';">- Look over notes and get clarification if needed

General-purpose exploratory questions <span style="font-family: 'Arial','sans-serif';">- Help interview along <span style="font-family: 'Arial','sans-serif';">- ‘Tell me about your typical day’ <span style="font-family: 'Arial','sans-serif';">- ‘Tell me three good things about’ <span style="font-family: 'Arial','sans-serif';">- ‘…Three bad things’

When to stop <span style="font-family: 'Arial','sans-serif';">- Balance practical constraints against comprehensiveness of the data <span style="font-family: 'Arial','sans-serif';">- Stop once no new insights are formed

//9.5 Obtaining information from people at a distance// <span style="font-family: 'Arial','sans-serif';">- Most common – questionnaire

Questionnaires: a cautionary note <span style="font-family: 'Arial','sans-serif';">- Streamline requirements process <span style="font-family: 'Arial','sans-serif';">- Good for large number of people <span style="font-family: 'Arial','sans-serif';">- Creating a workable questionnaire is difficult

Cultural probes <span style="font-family: 'Arial','sans-serif';">- Developed by Bill Gaver and colleagues in working with elderly people located in three European cities <span style="font-family: 'Arial','sans-serif';">- Aim was to design technologies which would foster greater participation in the community by older people. <span style="font-family: 'Arial','sans-serif';">- Got to know the groups in person, then introduced them to cultural probes packages <span style="font-family: 'Arial','sans-serif';">- Each person received collection of maps, postcards, disposable camera, and booklets o Each item stimulated interest and curiosity

//9.6 Working with groups// <span style="font-family: 'Arial','sans-serif';">- Alternative to questionnaires = focus groups <span style="font-family: 'Arial','sans-serif';">- Facilitators pose questions and encourage reactions <span style="font-family: 'Arial','sans-serif';">- Discussions flow more naturally <span style="font-family: 'Arial','sans-serif';">- Can be enhanced by scenarios and prototypes

//9.7 Observing activities in situ// <span style="font-family: 'Arial','sans-serif';">- Compliment interviews and questionnaires by observing people in action <span style="font-family: 'Arial','sans-serif';">- People describe how an activity is ‘supposed’ to be done, but not how it is actually executed <span style="font-family: 'Arial','sans-serif';">- Also important to identify what you have not observed because things may not go wrong while you are observing <span style="font-family: 'Arial','sans-serif';">- Being unobtrusive is difficult o The act of you watching someone work will make them act differently

//9.8 Artifact collection and ‘desk work’// <span style="font-family: 'Arial','sans-serif';">- Instead of using interviews, questionnaires and observation <span style="font-family: 'Arial','sans-serif';">- Designers work does not just involve working with the users, desk work is involved during the design process <span style="font-family: 'Arial','sans-serif';">- Desk work involves reading procedure manuals and other materials about the organization <span style="font-family: 'Arial','sans-serif';">- Studying existing software <span style="font-family: 'Arial','sans-serif';">- Collecting and analyzing documents that exist and documenting the movement of documents and the structure of object such as filing cabinets and ledger books. <span style="font-family: 'Arial','sans-serif';">- Market analysis: looks at similar products that have been produced o Way of getting new ideas

//9.9 Requirements and scenarios// <span style="font-family: 'Arial','sans-serif';">- Requirements are easier to illustrate using scenarios as well as presented in organized list