Microsoft PowerPoint enables you to create presentations for group seminars, employee orientations, client proposals and just about any business situation that an earlier generation handled with 35mm slides. If you treat every slide in your presentation as if it contains every point you're trying to make, you'll build an unreadable mess of small, crowded type that no one can or will want to read. The rule of 7x7 helps you serve up information in small, readily digestible doses that help you make your point.
You'll hear numerous versions of the rule of 7x7 -- 6x6, 5x5 and so on -- but the dictum boils down to two simple points. Don't put more than a specific number of lines of type on a single slide, and don't use more than that number of words on an individual line. If you overcrowd your slides, reduce your type size and even switch to a narrowly condensed typeface in an effort to cram more information onto each slide, you'll wind up displaying one of the primary symptoms of a bad presentation: the introduction in which you apologize for too-small type. Just say no to crowded slides and let the rule of 7x7 help you keep your vow.
Before you fall so much in love with the rule of 7x7 that you turn slide development into a bizarre form of haiku, focus on the primary point of any set of presentation materials. You're trying to convince, persuade, connect with and hold the attention of a group of people. If your audience participates involuntarily, either because you're presenting a mandated piece of continuing education or because you've required your employees to attend, you can meet with resistance when you seek your audience's attention. Don't make your job more difficult by filling every square inch of your slides with information, verbal or graphic.
If you're trying to reform the habit of slide cramming, implementing a line-by-line word count may help you retrain yourself and avoid overcrowding your slides. To reach the point at which 7x7 becomes second nature, remember what slides provide in the context of a presentation. You're not projecting a read-along clone of your talk. You're buttressing your argument with succinct bites of information, preferably adding to your narrative rather than simply echoing it.
If you're unsure whether your slides pass the test of uncrowded, accessible information, turn the tables on yourself and impersonate your audience before you turn your material loose on a live group. Sit at a standard audience viewing distance from your projector screen or computer monitor, and look at your material with a fresh set of eyes. If you can't read your text, split your slides up to make them readable. If your slides pass the 7x7 test but remain hard to read, courtesy of longer technical terminology, product model numbers or other terms that take up the space of multiple shorter words, overrule 7x7 in the interest of a readable, workable presentation.