As a product manager, you're probably responsible for many of the factors that affect your product's success in the market. One factor that doesn't always get its due, particularly in software offerings, is the impact of a well-planned and well-executed design.

A couple years ago, at the annual conference for a major vendor in the mobile device space, I attended a presentation by Donald Norman, the author of several highly respected books on various aspects of product design. Norman's previous works included "The Design of Everyday Things", and "The Invisible Computer". However, this particular lecture discussed some fairly new data that looked specifically at design in the context of the human emotional system. He cites several somewhat counter-intuitive studies that suggest purely aesthetic factors have a measurable effect on a product's performance. One study found, for example, that "attractive" ATM machines were considered easier to use than their less-attractive counterparts. This topic is explored at some length in his more recent book, "Emotional Design".

It's difficult to effectively summarize a 250 page book that is itself a summary of several other research efforts, but, in a (hopefully aesthetically pleasing) nutshell, Norman contends that people respond to a products design in three distinct modes: visceral, behavioral, and reflective.

Visceral reactions constitute the first emotional impression a person has to a new product and is generally tied to the product's appearance. Apple's iPod is a classic example of a product with strong visceral appeal. Norman contends that this initial reaction to a product is governed directly by the way in which the human brain and perceptual system have been wired over millennia of evolution. Certain shapes, sounds, colors, smells, etc. induce a sense of well-being, while others lead to a feeling of discomfort or potential danger. The brain actually functions differently in each of these conditions becoming more relaxed and creative in the former state, and highly focused and alert in the latter. These differences provide an explanation for the effect of aesthetics on product performance mentioned above -- people encountering a pleasing design felt less threatened by the new technology, and were able to more creatively explore alternatives when a particular path failed. By contrast, those facing an aesthetically-challenged design felt less at-ease, and hence became more focused on succeeding using a particular approach (tunnel-vision) and failed to try other potentially successful approaches.

Behavioral design refers to the overall experience and effectiveness of using a product for its intended purpose. A strong behavioral design is a necessary but not sufficient condition for a product's success. The cellphone market, for example, is littered with many striking and technically sophisticated designs that simply don't function well as phones.

Finally, reflective design refers to aspects of a product that leads people to acquire a product because of the statement it makes about their own personality. The intersection of the set of Toyota Prius owners with the set of Cadillac Escalade owners if probably fairly small, as the choice of these particular modes of transportation reflects, to some extent, the value system of the purchaser.

In summary, a conscious understanding of all three aspects of a product's design -- visceral, behavioral, and reflective -- can greatly increase the possibility of a product's success. Apple has proven to be a master at this as illustrated by the current television ad campaign contrasting Mac-Guy and PC-Guy. By creating products with strong visceral appeal (the iPod line), strong behavioral design (Mac's OS and software), and a strong reflective component as well (the army of Mac-heads), Apple has leveraged all three aspects of Norman's thesis to put forth a very strong product line.

For the record, I wrote this column on a run-of-the-mill laptop running Windows XP. I may need to reflect on that ...