# **4.4 Data Collection**

## **_Assignment of enumerators and interviewer effects_**

As enumerators, experts for each interview mode conducted interviews in their expertise. SORS has different groups of enumerators for F2F interviews as in HBS and the first round of LFS and for CATI surveys at the second or later round in LFS survey. In this way, each group could build their skill and experience on one of these interview modes.

A potential downside of this approach for this pilot was that the difference in enumerators’ skillset can cause a problem in comparability of data between the F2F and CATI surveys. In other words, the differences in data could be attributed to the differences in enumerators’ skillset. Instead, we thought it would be better to mix experts of F2F and CATI surveys and select them for F2F and CATI surveys randomly. Given that the assignment of enumerators is random, any difference in the resulting data between the F2F and CATI surveys cannot be attributed to the enumerators’ skillset and experiences.

However, the SORS team argued that using an enumerator for an interview mode with which he or she is not familiar can reduce the data quality significantly. This is an important consideration since the total number in the sample is limited. Furthermore, in reality, SORS will never use experts of F2F surveys for CATI surveys, and vice versa. Therefore, a right comparison should be between the F2F survey collected by the experts and the CATI surveys collected by the experts. After all these considerations, the SORS and the World Bank teams agreed to assign the F2F experts for the F2F survey and the CATI experts for the CATI survey.

## **_Training of enumerators_**

Interviewer training consisted of three blocks: (1) theoretical training for all interviewers, (2) practical training for field interviewers, and (3) practical training for telephone interviewers. The study objectives and the instructions on how to apply the different questionnaires, and how to identify respondents were explained. The Labor Force Survey (LFS) team explained administrative procedures and the questionnaire contents. The HBS team assisted in clarifying questions of the interviewers. The theoretical training ended with the filling of a demonstration vignette.

During the training for field interviewers, participants did a role-playing exercise, which consisted in asking the questions to another participant and filling the questionnaire with the answers. Participants were given a vignette and asked to fill in the questionnaire. The questionnaires were collected, marked and graded. Finally, participants were asked to fill a participant feedback form to evaluate the training.

A separate training session was held for telephone interviewers. First, the LFS team presented the electronic version of the questionnaire, developed in the Blaise platform, which participants were already familiar with. Second, participants did a role-playing exercise, an evaluation and filled the participant feedback form.

## **_Advance notification of interview visits_**

In order to maximize participation, this experiment followed the same procedure as surveys by SORS. For this respect, letters notifying households of upcoming visits by enumerators were sent out by SORS in advance. As World Bank (2013) discussed that the attrition rate in Peru’s result 14