My feeling is that this is a big question facing our field. In my view, we need both of these to be successful.

The argument runs something like this. If you are going to use those variables (frame data and paradata) for your nonresponse adjustments, then why bother using them to alter your data collection? Wouldn't it be cheaper to just use them in your adjustment strategy?

There are several arguments that can be used when facing these kinds of questions. The main point I want to make here is that I believe that this is an empirical question. Let's call X my frame variable and Y the survey outcome variable. If I assume that the relationship between X and Y is the same no matter what the response rate for categories of X, then, sure, it might be cheaper to adjust. But that doesn't seem to be true very often. And that is an empirical question.

There are two ways to examine this question. [Well, whenever someone says definitively there are "two ways of doing something," in my head, I'm thinking "at least two ways."] First, use existing data and simulate adjusted estimates at different response rates. Second, run an experiment. Compare the two methods. I think we actually need both of these things. It is an important question. We might as well be thorough in our research aimed at understanding it.

1. Shouldn't the question be: does adjusting data collection bring any improvements over just adjusting with weights? After all, just using weighting adjustment is most likely always cheaper than adjusting data collection, isn't it?

2. I agree that we would almost always want to adjust. I would say, on the other hand, that adjusting data collection might actually save costs. Groves and Heeringa had examples like that. And the title says controlling Costs and errors.

Yes, the assumption has to be verified. My guess, most of the time, we could benefit from adjusting data collection.

### "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…

### Is there such a thing as "mode"?

Ok. The title is a provocative question. But it's one that I've been thinking about recently. A few years ago, I was working on a lit review for a mixed-mode experiment that we had done. I found that the results were inconsistent on an important aspect of mixed-mode studies -- the sequence of modes.

As I was puzzled about this, I went back and tried to write down more information about the design of each of the experiments that I was reviewing. I started to notice a pattern. Many mixed-mode surveys offered "more" of the first mode. For example, in a web-mail study, there might be 3 mailings with the mail survey and one mailed request for a web survey. This led me to think of "dosage" as an important attribute of mixed-mode surveys.

I'm starting to think there is much more to it than that. The context matters  a lot -- the dosage of the mode, what it may require to complete that mode, the survey population, etc. All of these things matter.

Still, we ofte…