Not-so-hidden persuaders

by niamh on March 28, 2012

I’m currently spending a great semester in the US (at the University of North Carolina at Chapel Hill, a terrific institution with a long and distinguished history – see this! – and excellent academic standing: the very model of the modern public research university; so please don’t cut any more university education spending, NC legislature).

And this has given me an opportunity, among many others that is, to see some US TV close-up…

One thing that is striking, compared with European TV, is what is advertised and how. In particular,  I don’t think you see ads for prescription medicines in Europe, certainly not in Ireland or the UK. They seem to be all over American TV.

I am particularly struck by the way these ads are made. The visuals  typically show someone having a happy and trouble-free life while using these drugs, overlaid with soothing music and a reassuringly bland voice-over. But clearly the US FDA requires advertisers to include all the small print in their ads as well.

Do you read all the known downsides of the medicines you take? Don’t. The list of potential side-effects is usually pretty hair-raising, and hopefully most people won’t encounter them most of the time. So the voice-over has to balance the putative benefits of taking these drugs with all these possible side-effects. But if you actually listened right through to the end, I imagine the last thing you’d want to do is to expose yourself to even a small risk of any of them. Especially when there is another stream of ads by lawyers offering to take up your case and get you compensation for a whole range of damages caused by taking prescription medicines.

So my question is this. Clearly the advertisers think it’s worth running these ads despite the scarifying spoken bits. How does this work? Do they believe that consumers are more impressed by soft-focus pastel visuals and mood-music than by the words? Are consumers more affected by positive visual associations than by the audio information about risk?

We can’t assess the risk rationally ourselves, and I don’t think decision-theory is very helpful here, which is why we rely on regulators and professionals. Yet it seems the advertisers mean us to lobby our doctors to prescribe their brand-name drug. There must be lots of literature on the psychology of advertising that I don’t know about…

Evaluating students: the halo effect

by Chris Bertram on March 28, 2012

In the thread on community colleges (which morphed into a discussion of more general education and management issues), someone mentioned Kahneman on the “halo effect” in grading (or marking) student work. _Thinking Fast and Slow_ has been on my to-read pile since Christmas, but I got it down from the shelf to read the relevant pages. Kahneman:

bq. Early in my career as a professor, I graded students’ essay exams in the conventional way. I would pick up one test booklet at it time and read all the students’ essays in immediate succession, grading them as I went. I would then compute the total and go on to the next student. I eventually noticed that my evaluations of the essays in each booklet were strikingly homogeneous. I began to suspect that my grading exhibited a halo effect, and that the first question I scored had a disproportionate effect on the overall grade. The mechanism was simple: if I had given a high score to the first essay, I gave the student the benefit of the doubt whenever I encountered a vague or ambiguous statement later on. This seemed reasonable … I had told the students that the two essays had equal weight, but that was not true: the first one had a much greater impact on the final grade than the second. This was unacceptable. (p. 83)

Kahneman then switched to reading all the different students’ answers to each question. This often left him feeling uncomfortable, because he would discover that his confidence in his judgement became undermined when he later discovered that his responses to the same student’s work were all over the place. Neverthless, he is convinced that his new procedure, which, as he puts it “decorrelates error” is superior.

I’m sure he’s right about that and that his revised procedure is better: I intend to adopt it. Some off-the-cuff thoughts though: (1) I imagine some halo effect persists and that one’s judgement of an immediately subsequent answer to the same question in consecutive booklets or script is influenced by the preceding one; (2) reading answers to the same question over and over again can be even more tedious than marking usually is. I thing it would be even better to switch at random through the piles; (3) (and this may get covered in the book) the fact that sequence matters because of halo effects strikes me as a big problem for Bayesians. What your beliefs about something end up being can just be the result of the sequence in which you encounter the evidence. If right (and it’s not my department) then that ought to be a major strike against Bayesianism.