Completed Interview

The completed interview survey disposition is used in all types of surveys, regardless of mode. In a telephone or in-person interview, a completed interview results [Page 112]when the respondent has provided answers for all of the questions on the survey questionnaire that were asked by the interviewer. In a mail survey, a completed interview results when the respondent receives a paper-and-pencil survey questionnaire, answers all questions on the questionnaire, and returns the completed questionnaire to the researcher. In an Internet survey, a completed interview occurs when the respondent logs into the survey, enters answers for all of the questions in the questionnaire, and submits the questionnaire electronically to the researcher. Completed interviews are eligible cases and are considered a final survey disposition.

It is worthwhile to note that a completed interview usually indicates that the respondent has provided data (answers) for all applicable items on a questionnaire. However, at times respondents may answer most of the questions on a questionnaire but may accidentally skip or refuse to answer some questions on the survey instrument (called “item nonre-sponse”). Depending on how much data are missing, these interviews may be considered partial completions due to this item nonresponse but may also be considered breakoffs (or refusals) if the respondent began the interview or questionnaire but answered only a few of the applicable questions.

In practice, the level of item nonresponse may be very small, and it may be difficult to differentiate a completed interview from a partial interview. For this reason, most survey organizations have developed rules that explicitly define the differences among breakoffs, partial interviews, and completed interviews. Common rules used by survey organizations to determine whether an interview with item nonresponse can be considered a completed interview include (a) the proportion of all applicable questions answered; and (b) the proportion of critically important or essential questions administered. For example, cases in which a respondent has answered fewer than 50% of the applicable questions might be denned as breakoffs; cases in which the respondent has answered between 50% and 94% of the applicable questions might be denned as partial completions; and cases in which the respondent has answered more than 94% of applicable questions might be considered completed interviews.