### Paradata and Total Survey Error

At the recent Joint Statistical Meetings I was part of an interesting discussion on paradata and nonresponse. At one point, someone reported that their survey had reduced the number of observations being recorded by interviewers. They said the observations were costly in a double sense. First, it takes interviewer time to complete them. Second, it diverts attention from the task of gathering data from persons willing to respond to the survey.

I have to say that we certainly haven't done a very good job of determining the cost of these interviewer observations. First, we could look at keystroke files to estimate the costs. This is likely to be an incomplete picture as there are times when observations are entered later (e.g. after the interviewer returns home). Second, we could examine the question of whether these observations reduce the effectiveness of interviewers in other errors. This would require experiments of some sort.

Once these costs are understood, then we can place them in a total survey error perspective. These observations have some cost. Is that cost justified by their utility in reducing nonresponse biases? For example, for a fixed budget obtaining these observations might require that I reduced my sample size by a certain amount (possibly by lowering the response rate). But the accuracy of weighted estimates might improve with these interviewer observations such that the total error is reduced.

I don't know of any evaluations of interviewer observations from this perspective. But it seems like a logical next step.

### "Responsive Design" and "Adaptive Design"

My dissertation was entitled "Adaptive Survey Design to Reduce Nonresponse Bias." I had been working for several years on "responsive designs" before that. As I was preparing my dissertation, I really saw "adaptive" design as a subset of responsive design.

Since then, I've seen both terms used in different places. As both terms are relatively new, there is likely to be confusion about the meanings. I thought I might offer my understanding of the terms, for what it's worth.

The term "responsive design" was developed by Groves and Heeringa (2006). They coined the term, so I think their definition is the one that should be used. They defined "responsive design" in the following way:

1. Preidentify a set of design features that affect cost and error tradeoffs.
2. Identify indicators for these costs and errors. Monitor these during data collection.
3. Alter the design features based on pre-identified decision rules based on the indi…

### An Experimental Adaptive Contact Strategy

I'm running an experiment on contact methods in a telephone survey. I'm going to present the results of the experiment at the FCSM conference in November. Here's the basic idea.

Multi-level models are fit daily with the household being a grouping factor. The models provide household-specific estimates of the probability of contact for each of four call windows. The predictor variables in this model are the geographic context variables available for an RDD sample.

Let $\mathbf{X_{ij}}$ denote a $k_j \times 1$ vector of demographic variables for the $i^{th}$ person and $j^{th}$ call. The data records are calls. There may be zero, one, or multiple calls to household in each window. The outcome variable is an indicator for whether contact was achieved on the call. This contact indicator is denoted $R_{ijl}$ for the $i^{th}$ person on the $j^{th}$ call to the $l^{th}$ window. Then for each of the four call windows denoted $l$, a separate model is fit where each household is assum…

### Future of Responsive and Adaptive Design

A special issue of the Journal of Official Statistics on responsive and adaptive design recently appeared. I was an associate editor for the issue and helped draft an editorial that raised issues for future research in this area. The last chapter of our book on Adaptive Survey Design also defines a set of questions that may be of issue.

I think one of the more important areas of research is to identify targeted design strategies. This differs from current procedures that often sequence the same protocol across all cases. For example, everyone gets web, then those who haven't responded to  web get mail. The targeted approach, on the other hand, would find a subgroup amenable to web and another amenable to mail.

This is a difficult task as most design features have been explored with respect to the entire population, but we know less about subgroups. Further, we often have very little information with which to define these groups. We may not even have basic household or person chara…