Computer-assisted personal interviewing (CAPI) is an interviewing technique in which the respondent or interviewer uses an electronic device to answer the questions. It is similar to computer-assisted telephone interviewing, except that the interview takes place in person instead of over the telephone. This method is usually preferred over a telephone interview when the questionnaire is long and complex. It has been classified as a personal interviewing technique because an interviewer is usually present to serve as a host and to guide the respondent. If no interviewer is present, the term Computer-Assisted Self Interviewing (CASI) may be used. An example of a situation in which CAPI is used as the method of data collection is the British Crime Survey.
Characteristics of this interviewing technique are: Either the respondent or an interviewer operates a device (this could be a laptop, a tablet or a smartphone) and answers a questionnaire. The questionnaire is an application that takes the respondent through a set of questions using a pre-designed route based on answers given by the respondent. Help screens and courteous error messages are provided. Colorful screens and on and off-screen stimuli can add to the respondent's interest and involvement in the task. This approach is used in shopping malls, preceded by the intercept and screening process. CAPI is also used to interview households, using sampling techniques like random walk to get a fair representation of the area that needs to be interviewed. It is also used to conduct business-to-business research at trade shows or conventions.
Advantages CAPI
The face-to-face setting allows the interviewer to capture verbal and non-verbal feedback. Personal interviewing allows for interviews of longer duration. Interviews of 45 minutes or more are not uncommon. Modern devices can record audio feedback from respondent, track GPS location and allows pictures to be taken of the interview, thus adding to the quality of the data. There is no need to transcribe the results into a computer form. The computer program can be constructed so as to place the results directly in a format that can be read by statistical analysis programs such as PSPP or DAP. The presence of an interviewer helps when probing for spontaneous awareness of certain topics. The interviewer can verify that the respondent answering the questions is the person that needs to be interviewed.
Disadvantages CAPI
It is a relatively expensive means of interviewing. In comparison to web interviewing it can be more time consuming to gather data.
Computer-Assisted Self Interviewing (CASI) The big difference between a computer-assisted self interview (CASI) and a computer-assisted personal interview (CAPI) is that in the latter an interviewer is present, but not in the former. There are two kinds of computer-assisted self interviewing: a "video-CASI" and an "audio-CASI". Both types of computer-assisted self interviewing might have a big advantage over computer-assisted personal interviewing, because subjects could be more inclined to answer sensitive questions. The reason for this is that they feel that a CASI is more private due to the absence of an interviewer.
Advantages CASI
This form of interview is substantially cheaper when a large number of respondents is required, because: There is no need to recruit or pay interviewers. Respondents are able to fill in the questionnaires themselves. The program can be placed on a web site, potentially attracting a worldwide audience. Another advantage is that there is more likely hood of getting true and honest responses from the subjects in very sensitive matters.
Disadvantages CASI
The survey is likely to attract only respondents who are "computer savvy", thus introducing potential bias to the survey. The survey can miss feedback and clarification/quality control that a personal interviewer could provide. For example, a question that should be interpreted in a particular way, but could also be interpreted differently, can raise questions for respondents. If no interviewer is present, these questions will not be answered, potentially causing bias in the results of the questionnaire.