Introduction to Statistics for Built Environment

Course Code: AED 1222

Compiled byDEPARTMENT OF ARCHITECTURE AND ENVIRONMENTAL DESIGN (AED)

CENTRE FOR FOUNDATION STUDIES (CFS)INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA

The next step after the sample is identified and selected using one or more of the techniques discussed earlier, is to determine the best way to reach respondents in order to obtain the required data.

As a basic rule, the researcher must choose the method that provides the most information at minimum cost.

Data collection methods

Business Statistics: A Decision-Making Approach, 7e © 2008 Prentice-Hall, Inc.

Data Collection Methods

Questionnaires surveyExperiments

Telephone interview

Direct observation and personal face-to-face interview

Mail / Postal questionnaires

Data collection methods cont…

1.THE EXPERIMENT: a test or treatment is deliberately imposed on the individuals/subject in order to observe a possible change in the response or variable being measured.

Advantages: results in a new and more accurate finding, subject will respond (or not) and the experimenter may be able to measure the result.Disadvantages: may be time consuming and costly.

Data collection methods cont…

2. THE FACE-TO-FACE INTERVIEW: a.k.a. the personal interview where the interviewer asks the questions and records responses.

Advantages: results in a higher response rate, peoples will respond spontaneously when interviewed personally, the interviewer may be able to detect false information.Disadvantages: may be costly, the interviewer must be carefully selected, facial expressions and statements by interviewers may influence and affect responses.

Data collection methods cont…

3. THE TELEPHONE INTERVIEW: a usually short interview where the interviewer asks questions from a prepared questionnaire.

Advantages: less expensive than face-to-face interviews, allows the researcher to monitor the recorded telephone interviews.Disadvantages: lower response rates, limited to a few questions as it may not be convenient for respondents to answer too many questions.

Data collection methods cont…

4. THE QUESTIONNAIRE SURVEY: here the researcher will personally explain to respondents his/her intentions before giving them a questionnaire.

Advantages: speed in obtaining required data, higher response rate, the interviewer is available to attend to any query by respondents.Disadvantages: expensive as it may involve considerable transportation expenditure, research coverage may not be as large as that achieved with the postal questionnaire.

Data collection methods cont…

5. MAIL OR POSTAL QUESTIONNAIRE: here a questionnaire is sent to each respondent, with a request to answer and return the questionnaire within a certain period of time.

Advantages: cheaper than the personal interview, it allows for greater research coverage, there is no interviewer influence, sufficient time given to respondents to think of appropriate answers.Disadvantages: low response rate, there is nobody who could readily explain unclear questions to respondents, no way of detecting false data, may be filled by a team not an individual thus rendering it useless, there may be a considerable delay before enough replies are received.

Data collection methods cont…