ISElective1_CM7

ISElective1_CM7

activities progress in a sequential manner

first gather some data, interpret, extract some requirements, process iterates

Imply that requirements exist out there and we simply need to pick them up or catch them.

Gathering and Capturing

Implies that "others" (presumably the clients or users) know the requirements and we have to get them to tell us.

Elicitation

Normally used to describe the activity of investigating and analyzing an initial set of requirements that have been gathered, elicited, or captured.

requirements analysis

recognizes that developing a set of requirements is an iterative process of evolution and negotiation, and one that needs to be carefully managed and controlled.

Requirements Engineering

Statement about an intended product that specifies what it should do or how it should perform.

requirement

Different Kinds of Requirements:

Different Kinds of Requirements (Traditional): Functional Requirement

Different Kinds of Requirements:

Different Kinds of Requirements (Traditional): Non-Functional Requirement

Different Kinds of Requirements: Capture what the product should do

Different Kinds of Requirements (Interaction Design): Functional Requirements

Different Kinds of Requirements: Capture the type, volatility, size/amount, persistence, accuracy, and value of the amounts of the required data

Different Kinds of Requirements (Interaction Design): Data Requirements

Different Kinds of Requirements: Refer to the circumstances in which the interactive product will be expected to operate

Different Kinds of Requirements (Interaction Design): Data Requirements

Environmental Requirements: dusty? noisy? vibration? light? heat? humidity?

Environmental Requirements: Physical Environment

Environmental Requirements: sharing of files, of displays, in paper, across great distances, work individually, privacy for clients

Environmental Requirements: Social Environment

Environmental Requirements: user support, facilities or resources for training, stability of communication infrastructure, hierarchy in the management;

Environmental Requirements: Organizational Environment

Environmental Requirements: what technologies will the product run on, compatibility, and technological limitations

Environmental Requirements: Technical Environment

Capture the characteristics and attributes (User Profile) of the intended user group

A user may be a novice (needs step-by-step, constrained and clear information), an expert (flexibilty, access/power), a casual (clear instructions), or a frequent user (shorcuts)

Different Kinds of Requirements (Interaction Design): User Requirements

Capture the usability goals and associated measures for a particular product
effectiveness, efficiency, safety, utility, learnability, and memorability

Different Kinds of Requirements (Interaction Design): Usability Requirements

important part of the requirements activity and also of evaluation

Data gathering

6 Data gathering techniques

questionnaires, interviews, focus groups and workshops, naturalistic observation, and studying documentation.

• A series of questions designed to elicit specific information
• Questions may require different kinds of answers: (1) simple YES/NO, (2) choice of pre-supplied answer, (3) comment
• are sent in electronic form and arrive via email or are posted on a website, and sometimes they are given on paper
• In most cases the questionnaire is administered at a distance
• Good for answering specific questions from a large, dispersed group of people

Data gathering techniques: Questionnaires

• involve asking someone a set of questions
• often conducted face-to-face but not necessary, may also be in telephone interview
• can be structured, unstructured or semi-structured
• are good at getting people to explore issues
• time consuming and it may not be feasible to interview all the people

Data gathering techniques: Interview

are good at gaining a consensus view and/or highlighting areas of conflict and disagreement

Data gathering techniques: Groups and Workshops

• involves spending some time with the stakeholders as they go about their day-to-day tasks, observing work as it happens, in its natural setting
• A member of the design team shadows a stakeholder, making notes, asking questions (but not too many), and observing what is being done in the natural context of the activity
• Requires time and commitment from a member of the design team, and it can result in a huge amount of data

Data gathering techniques: Naturalistic Observation

Procedures and rules are often written down in manuals and these are a good source of data about the steps involved in an activity and any regulations governing a task

Data gathering techniques: Studying Documentation

suggest that choosing between data-gathering techniques rests on two issues: the nature of the data gathering technique itself and the task to be studied.

Olson and Moran (1996)

Data gathering techniques differ in two ways:

1. Amount of time, level of detail and risk associated with the findings

2. Knowledge the analyst requires

an "informal narrative description" (Carroll, 2000). It describes human activities or tasks in a story that allows exploration and discussion of contexts, needs, and requirements. It does not explicitly describe the use of software or other technological support to achieve a task.

scenario

emphasizes on a user-system interaction rather than the user's task itself. A ______ is associated with an actor, and it is the actor's goal in using the system that the use case wants to capture.

Use cases

represent abstractions from scenarios, i.e., they represent a more general case than a scenario embodies, and try to avoid the assumptions of a traditional use case.

structured narrative consisting of three parts: a name that expresses the overall user intention, a stepped description of user actions, and a stepped description of system responsibility.

Essential use cases

used mainly to investigate an existing situation, to envision new systems or devices. It is used to analyze the underlying rationale and purpose of what people are doing: what are they trying to achieve, why are they trying to achieve it, and how are they going about it.

Task analysis

originally designed to identify training needs (Annett and Duncan, 1967). It involves breaking a task down into subtasks and then into sub-subtasks and so on. These are then grouped together as plans that specify how the tasks might be performed in an actual situation.

Hierarchical Task Analysis (HTA)