so here we are

I am back in Dar es Salaam, back at Twaweza, and back working on mobile data gathering. Before giving you an overview about the things that will be happening in the weeks to come, I will first use this post to recapitulate where we are coming from.

During August/September last year, we went into the field to draw a stratified sample of 550 respondents in Dar es Salaam, conducting face-to-face household interviews. Our extensive survey covered quite an impressively broad range of topics such as family composition, work situation, political orientations, infrastructure, health issues and children’s education (actually, given that the survey took about 1,5h to complete, I was somewhat surprised to see that almost all people took the time to answer all of our questions and that non-response rates were minimal). After completion of the questionnaire, respondents were asked if they owned or had access to a mobile phone. If so, we invited them to participate in follow-up mobile surveys. Out of those respondents that we interviewed, 76% had their own mobile phone and another 12,5% had access to the phone of another household member.

In the weeks after the baseline survey was finished, an infrastructure was set up by DataVision to call respondents for short surveys (10-15 questions) and transfer small credit top-ups after the interview as incentives. Initially, we also had planned to use USSD and IVR (and even a web application), but the technical difficulties in putting these in place seemed more serious than expected, and we resorted to simply calling respondents during the weekends.

The mobile survey system was up and running by January 2011, and in the following 18 weeks, respondents were called weekly and a rich body of real-time data were gathered, mainly about the quality of public services such as education, health, garbage collection, water and electricity. After some substantial drop-out in the first weeks, the panel size quickly stabilized around 330. Each weekend, respondents were called by the same interviewers, contributing to   sense of commitment so crucial for preventing attrition in panels.

Why people drop out
To get a better understanding of the reasons for non-contact / non-response, a field re-visit to nonparticipating respondents was organized four weeks into the mobile data gathering. Interviews revealed that the main factors that contributed to panel drop-out were the widespread sharing of handhelds, mobiles that were lost or stolen, the use of multiple SIM cards, lack of reliable electricity to charge phone and the fact that some respondents had only resided in the city temporarily.

About three weeks ago, the data gathering was temporarily paused as the whole project was transferred from Twaweza to the World Bank. Interested in exploring the potential of mobile surveys for independent third party monitoring, the World Bank will be running the panel for six months, conducting biweekly surveys on topics related to its activities in Dar es Salaam.

So this is where we are.

But there is more to come:
To correct the bias in our mobile sample created by the lack of phone access in baseline respondents, we will be heading back into the field shortly to hand out 50 mobile phones. Also, we now seem to be ready to throw in two new technologies as data gathering channels: USSD and IVR. More on all this very shortly.

This entry was posted in call center, IVR, nonresponse, sampling, USSD. Bookmark the permalink.

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