Chances are your organization has lots of compelling features and benefits. Most do. But when crafting a proposal or presentation, how many should you highlight for your prospect? Five? 10? According to cognitive psychologists, it's probably less than you think.

That's why, in continuing my discussion of simplicity, I'm examining your prospects' short-term memory capacity. How many features/benefits do they actually retain when processing your information, and what are the implications for your proposals and presentations? Let's find out.

The famous number seven, plus or minus two

You may have heard that you should limit groups of information — such as items on a PowerPoint slide, bullets in a list or key messages in a document — to no more than seven. But why?

It all goes back to a 1956 paper by George Miller, in which he states that a typical adult's short-term memory span is five to nine meaningful chunks of information. By "meaningful," Miller meant groups of items that can be remembered as a single unit.

For example, let's say someone read the following 12 digits to you at a rate of one per second: 1 7 7 6 3 6 5 9 0 2 1 0. In this case, you'd likely be able to recall roughly seven digits in the correct order. However, if the speaker was to insert pauses in their speech, thereby grouping the numbers into three meaningful chunks — 1776 (the year America declared independence), 365 (days in a year) and 90210 (TV show) — you'd easily recall all 12 digits in order.

This sounds logical, and a lot of people have assumed the limit of seven chunks, plus or minus two, as fact. Indeed, Miller's research has become not only one of the most commonly cited papers in psychology, but also the guidepost for all sorts of generally accepted rules of presenting and persuasive writing.

As a result, the average company now communicates six to eight features/benefits (chunks of information) to prospects in their proposals and presentations, according to a study by the Persuasion Institute.

Modern misconceptions

So case closed, right? Wrong. The same Persuasion Institute study found that of those six to eight features/benefits, only one, two or three are actually retained, and 40 percent of prospects remember one of the features/benefits incorrectly.

Furthermore, even Miller himself has clarified that the "magic number seven" expression was used rhetorically, and that his point was that seven is a limit for immediate recall, not comprehension or longer-term recall of printed text or verbal communication in a presentation.

The practical magic number

So what's the real magic number of benefits to highlight? Well, the latest research has found that many factors affect your prospects' short-term memory spans — such as the environment and type of information chunks used — so an exact number is difficult to discern. However, most studies suggest that your target should be more like three, plus or minus one.

For instance, Nelson Cowan conducted some of the most comprehensive research, and his studies determined that the optimum number is four. Studies by Max Coltheart agree with Cowan's conclusions, while studies by D.E. Broadbent found the optimum number to be three. Meanwhile, studies by Fernand Gobet and Gary Clarkson found that the average adult short-term memory holds only a little over two chunks of information.

The bottom line: Focus the messaging of your proposals and presentations on the three most important benefits your services/products provide to your prospects, and never go above four.

The big caveat

Before you dash off to craft three features/benefits for your executive summary or first PowerPoint slide, keep this in mind: No matter how few chunks are provided, unless the information is kept active in your prospects' short-term memory, it will be quickly forgotten. How quickly? Try 18 seconds.

So how do you ensure that your key benefits are kept active for long-term recall? I'll be tackling that question — particularly the importance of repetition, variety and graphic components — in my next entry.