One possibility is that the diver on page 115 appears to be pointing with his thumb to a Spotfin butterflyfish instead of a Foureye Butterflyfish. Another is that the Foureye butterflyfish in the drawings on pages 114 and 116 show a black eye band while the eyeband in the pictures on page 115 looks iridescent to me, not black.

Am I on the right track or is the problem something else entirely?

In the February 2002 issue of the Harvard Business Review there is an excellent aricle on the design of workplace surveys:

"Getting the Truth into Workplace Surveys," by Palmer Morrel-Samuels.

The article is not available on-line, but you can look at the absract and order a copy here.

I heartily recommend it to anyone involved in the creation of surveys. Here is a brief excerpt to show you what it is like:

Guideline 4: Keep sections of the survey unlabeled and uninterrupted by page breaks.

Boxes, topic labels, and other innocuous-looking details on surveys can skew responses subtly and even substantially. The reason is relatively straightforward: As extensive research shows, respondents tend to respond similarly to questions they think relate to each other. Several years ago, we were asked to revise an employee quesionnaire for a large parcel-delivery service based in Europe. The survey contained approximately 120 questions divided into 25 sections, with each section having its own label ("benefits," "communication," and so on) and set off in its own box. When we looked at the results, we spotted some unlikely correlations between average scores for certain sections and corresponding performance measures. For example, teamwork seemed to be negatively correlated with on-time delivery.

A statistical test revealed the source of the problem. Quesions in some sections spanned two pages and therefore appeared in two separate boxes. Consequently, respondents treated the material in each box as if it addressed a separate topic. We solved the problem by simply removing the boxes, labels, and page breaks that interrupted some secions. The changes in formatting encouraged respondents to consider each question on its own merits; although the changes were subtle, they had a profound impact on the survey results.

Is it better when making a presentation with a Proxima(tm) type projector to use light/white text with a dark background or dark text with a light/white background?

I'm wondering if you've come across this nifty example of a polar diagram invented by Florence Nightingale.

[Editor's note: A good account of Florence Nightingale's statistical diagrams is here, at the website of the Florence Nightingale Museum.]

This has nothing to do with information design, but I thought I'd point out what appears to be an error in your description of the 'Downs Eureka Pass' sleight of hand.

Briefly (for those who don't have the book): a magician with his right hand makes a coin seem to vanish while in fact concealing it behind his fingers. The left hand then openly transfers a second coin to the right, surreptitiously taking the first, hidden one in the process. The right hand then 'vanishes' the second coin in the same manner as the first, and the cycle can repeat.

ET writes: "Since the left hand must hide an increasing accumulation of potentially clinking coins, the repeated cycles grow more difficult."

Surely, only two coins are required, and neither hand ever holds more than one. The 'vanished' one becomes, moments later, the next 'new' one apparently drawn from a nonexistent supply in a pocket or other container.

The 'reverse' of this effect is to make coins 'appear' in the right hand by essentially the same technique. The left hand in taking the coin loads a second one into the concealed position, so another coin can appear in the right moments later. Usually the magician will with his left hand pretend to drop the just -appeared coin into a metallic pail, which emits a nice loud 'clink' to signal that the coin has hit the bottom. In fact, there's a device hidden in the pail which creates a false noise, as the magician conceals the first coin again in his left hand, for transport back to the right as the cycle repeats. The audience doesn't actually see the coins falling into the pail ("Hey, why doesn't he use a glass bowl?") but their ears get the message, and believe.

We now return you to your regularly scheduled topics...