1. Requirements Engineering
University of Palestine
Faculty of Engineering and Urban planning
Software Engineering department
Requirements Engineering
Lecture 6 of
RQE Elicitation
Mohammad Amin Kuhail M.Sc. (York, UK)
Tuesday, 2 October 2007

2. Elicitation Techniques
Questioners
Use Cases
Role Playing
Prototyping

3. Elicitation Techniques
questionnaires
Questionnaires are mainly used during the early stages of requirements elicitation and may consist of open and/or closed questions.
Questions must be focused to avoid gathering large amounts of redundant and irrelevant information. They provide an efficient way to collect information from multiple stakeholders quickly, but are limited in the depth of knowledge they are able to elicit.
opportunity to delve further on a topic, or expand on new ideas. In the same way they provide no mechanism for the participants to request clarification or correct misunderstandings.

4. Elicitation Techniques
Questionnaires Issues:
The research objectives and frame of reference should be defined beforehand, including the questionnaire's context of time, budget, manpower, intrusion and privacy.
The nature of the expected responses should be defined and retained for interpretation of the responses, be it preferences (of products or services), facts, beliefs, feelings, descriptions of past behavior, or standards of action.
Unneeded questions are an expense to the researcher and an unwelcome imposition on the respondents. All questions should contribute to the objective(s) of the research.
The topics should fit the respondents’ frame of reference. Their background may affect their interpretation of the questions. Respondents should have enough information or expertise to answer the questions truthfully.

5. Elicitation Techniques
Questionnaires Issues:
Questions and prepared responses to choose from should be neutral as to intended outcome. A biased question or questionnaire encourages respondents to answer one way rather than another. Even questions without bias may leave respondents with expectations.
The order or “natural” grouping of questions is often relevant. Prior previous questions may bias later questions.
If a survey question actually contains more than one issue, the researcher will not know which one the respondent is answering. Care should be taken to ask one question at a time.
Most people will not answer personal or intimate questions.
Presentation of the questions on the page (or computer screen) and use of white space, colors, pictures, charts, or other graphics may affect respondent's interest or distract from the questions.
Numbering of questions may be helpful.

6. Elicitation Techniques
Questionnaires Types of Questions:
Contingency questions - A question that is answered only if the respondent gives a particular response to a previous question. This avoids asking questions of people that do not apply to them (for example, asking men if they have ever been pregnant).
Matrix questions - Identical response categories are assigned to multiple questions. The questions are placed one under the other, forming a matrix with response categories along the top and a list of questions down the side. This is an efficient use of page space and respondents’ time.
Yes/no questions - The respondent answers with a “yes” or a “no”.
Multiple choice - The respondent has several option from which to choose.
Scaled questions - Responses are graded on a continuum (example : rate the appearance of the product on a scale from 1 to 10, with 10 being the most preferred appearance).
Open ended questions - No options or predefined categories are suggested. The respondent supplies their own answer without being constrained by a fixed set of possible responses. Examples of types of open ended questions include:
Completely unstructured - For example, “What is your opinion of questionnaires?”
Word association - Words are presented and the respondent mentions the first word that comes to mind.
Sentence completion - Respondents complete an incomplete sentence. For example, “The most important consideration in my decision to buy a new house is . . .”

7. Elicitation Techniques
Questionnaires Sequence:
Questions should flow logically from one to the next.
The researcher must ensure that the answer to a question is not influenced by previous questions.
Questions should flow from the more general to the more specific.
Questions should flow from the least sensitive to the most sensitive.
Questions should flow from factual and behavioral questions to attitudinal and opinion questions.
Questions should flow from unaided to aided questions
According to the three stage theory (also called the sandwich theory), initial questions should be screening and rapport questions. Then in the second stage you ask all the product specific questions.

8. Elicitation Techniques
Use cases
A use case is a technique used in software and systems engineering to capture the functional requirements of a system.
Use cases describe the interaction between a primary actor—the initiator of the interaction—and the system itself, represented as a sequence of simple steps.

9. Elicitation Techniques
Use cases types (in terms of degree details)
A casual use case consists of a few paragraphs of text, summarizing the use case.
A brief use case consists of a few sentences summarizing the use case. It can be easily inserted in a spreadsheet cell, and allows the other columns in the spreadsheet to record priority, technical complexity, release number, and so on.
A fully dressed use case is a formal document based on a detailed template with fields for various sections; and it is the most common understanding of the meaning of a use case. Fully dressed use cases are discussed in detail in the next section on use case templates.

10. Elicitation Techniques
Types of use cases:
The business use case is described in technology free terminology which treats the business process as a black box and describes the business process that is used by its business actors (people or systems external to the business) to achieve their goals (e.g., manual payment processing,). The business use case will describe a process that provides value to the business actor, and it describes what the process does.
The system use cases are normally described at the system functionality level (for example, create voucher) and specify the function or the service system provides for the user. A system use case will describe what the actor achieves interacting with the system. For this reason it is recommended that a system use case specification begin with a verb (e.g., create voucher, select payments, exclude payment, cancel voucher). Generally, the actor could be a human user or another system interacting with the system being defined.

11. Elicitation Techniques
Use case template
Typical template contains:
Use case name
Primary, Secondary actors
Summary
Preconditions
Triggers
Basic course of events
Alternative paths
Exceptions
Postconditions
Business rules
Notes
Author and date

12. Elicitation Techniques
When to use it
Normally, domain experts and business analysts should be involved in writing use cases for a given system.
Use cases are created when the requirements of a system need to be captured. Because, at this point no design or development activities are involved, technical experts should not be a part of the team responsible for creating use cases. Their expertise comes in use later in the software lifecycle.

13. Elicitation Techniques
Example

14. Elicitation Techniques
Rules
Extends
Includes
Example: View course