Can we really do two things at once?

Like most research companies mine now routinely includes cell phones in our telephone samples. Best practice requires that before we interview someone on a cell phone we determine if it's safe to do the interview. If, for example, the respondent is driving a car we don't do the interview. Yesterday someone asked me if it was ok to do the interview if the respondent is using a hands-free device. The research on this is pretty clear: the problem with cells phones and driving is the distraction, not the dexterity required to hold a phone in one hand and drive with the other.  There is no basis for making an exception for hands-free.

This reminded me that responding to survey questions is not easy; it takes some serious cognitive energy. Most researchers accept the four-step response process described a decade ago by Tourangeau, Rips and Rasinski:

1. Comprehension—understand the question and how to answer it (instructions)
2. Retrieval—search memory to form an answer
3. Judgment—assess completeness and relevance of the answer
4. Respond—map the response onto the right response category

When respondents execute this process faithfully we say they are engaged. When they short-circuit it we talk about lack of engagement. A person talking on a cell phone while driving can either drive or engage with the survey. It's a rare person who can do both well simultaneously.

Which brings us to one of my favorite subjects: respondent engagement and rich media (aka Flash) in Web surveys. What is the rationale for arguing that dressing a Web survey up with more color, pimped-up radio buttons, a slider bar, or a slick drag and drop answering device is going to encourage respondents to execute the four-step response process with greater care than if we just show them the same kind of standard screen they use to enter their credit card details on Amazon? Or are unfamiliar interfaces just a distraction that makes it even less likely? It might get someone to the next question, but is that enough?