Personal (Face to Face) interviews

Personal interviews can be conducted in the respondent’s home or workplace, or in locations such as shopping malls, or even simply on the street.

Computer Assisted Personal Interviewing (CAPI) involves the interviewer using a laptop to record the respondent’s answers. The questionnaire is programmed onto the laptop using specialist software (e.g. Blaize). This software enables the interviewer to record the responses and then routes the interviewer automatically to the next appropriate question.

Advantages and Disadvantages of Personal Interviews

Advantages Disadvantages

• CAPI allows for a more efficient survey process since validation checks and coding can be done at the time of interview. Also, the electronically held responses can be transferred back to the survey centre quickly following the interview.

• As with CATI, the cost of setting up and maintaining the questionnaire software and computer technology is high.

• The response rate is usually high for personal interviews as the respondent typically finds it difficult to refuse an interviewer face-to-face compared to over the telephone.

• Making contact with the desired respondent may be difficult, as the respondent may not be home when the interviewer calls. Repeated attempts to contact should be made but these will inevitably increase costs.

• Data quality tends to be good since the interviewer can probe for more complete answers from the respondent and can complete validation checks at the time of interview. As the interviewer is present to answer queries, more complex questions designed to elicit detailed information can be asked.

• Interviewer bias may occur if the interviewer is poorly trained. The interviewer may consistently misinterpret responses or give misleading guidance. Bias may also be introduced through the interviewer appearance, gender, age, ethnicity and tone of voice.

• Visual aids, or ‘flash’ cards can be used to help the respondent to answer certain sensitive

• Compared to self-completion and telephone interviews, personal interviews are

behaviour or drug addiction. employing and training interviewers for the survey, along with paying for the interviewers travel and subsistence costs. Such costs may be minimised depending on the sampling method used. • Since only the interviewer need

understand the questionnaire structure, complex routing and filtering may be used in the questionnaire.

4. Diaries

Diaries are used as data collection instruments to collect detailed information about behaviour, events and other aspects of individuals daily lives. Respondents are given a diary to complete at regular (usually predetermined) intervals, for a set period of time.

Diaries provide an alternative method to interviews for events that are easily forgotten or difficult to recall. They are often used in combination with personal interviews. The diary provides the main data collection instrument and the interview is used to collect background information from the respondent, and information that may be of interest to the study that will not be captured by the diary. During the interview, interviewers will explain to the respondent how the diary is to be kept. Diaries can be open format, allowing respondents to record activities and events in their own words, or they can be highly structured where all activities are pre-categorised. All diary surveys, regardless of their format, need highly trained coding and analysis staff and an exhaustive and mutually exclusive coding structure is paramount to the success of the survey analysis. (The importance of coding will be discussed later in this module.)

Advantages and Disadvantages of Diaries

Advantages Disadvantages

• The open format of a diary allows respondents to answer in detail and gives the respondent opportunity to clarify the meaning of their response.

• There are significant costs involved with this method. The

costs incurred from accompanying this method with

personal interviews are added to by the labour intensive editing and coding processes that are needed for data analysis.

respondents may not complete the diary at each relevant time period, the recall time required is much less than when an interview or a self-completion questionnaire is used.

may become more aware of their behaviour and adjust their behaviour accordingly to comply more with the norms of society.

• The accuracy and quality of data collected within a diary survey is high.

• Diaries often suffer from what is known as “first day effects”. This is where respondents are diligent for the first day of the collection period, entering accurately and promptly their response. After the first day their enthusiasm for the survey may wane and their responses become less prompt, meaning that the accuracy of their inputs will rely on memory.

• It is possible that responses will

reveal the unexpected.

• Members of the chosen sample may refuse to take part in the survey. Reassurances of confidentiality and offering incentives to respondents will

influence respondent’s cooperation. The success of the

survey may also depend on the quality of interviewing staff who should be highly motivated, competent and well briefed, thereby encouraging response. • Diaries can be designed so that

they provide a form for respondents to complete.

• Diaries are time consuming and may become tedious, if a diary is to be fully completed over a reasonable period.

• It is possible to use different diaries for different sub-groups within the population. For example the Living Cost and Food Survey uses more detailed diaries for adults than it does for children.

• Diaries, as with all self- completion questionnaires, rely on assumed level of literacy and as such they disadvantage the less literate respondents. In some cases this assumed literacy level will mean that the sample used is biased in favour of the more literate from the population.

Although the design of a diary will depend on the detailed requirement of the topic under consideration, there are certain design aspects which are common to most:

• The diary should include clear instructions on how to complete the diary. These instructions should stress the need for the entries to be placed in the diary as soon as possible after the event.

• An example should be given of how the diary is to be completed. • Each page of the diary should be for a specific period. For

example a day or week.

• A checklist of what should and shouldn’t be included in the diary should be given.

• Terminology that can be recognised by the respondents should be used.

• At the end of the diary a series of questions on the diary itself should be asked. These should include any comments or feelings that respondents have on completing the diary.

Exercise 3

Taken from 2004, Paper I, Question 5

In dietary studies, subjects are sometimes asked to keep a diary for a limited period of time in which they record what foods and drinks they have consumed, and when. Outline the advantages and disadvantages of collecting information using a diary rather than relying solely on a questionnaire.