Topical navigation bears a strong resemblance to Nested Navigation on the surface. In fact, the two styles seem almost identical from the audience's perspective. The differences lie below the surface, in the design logic.
In Nested navigation, the upper links jump to external shows and the lower links stay within the current presentation. With Topical navigation, however, the upper links stay within the same presentation as well. In other words, this style divides a single, long, linear show into subcategories. Such divisions help a presenter find and display individual slides quickly, even if the show contains 200 or 300 slides.
Topical navigation is more limited in scope than Nested style but works especially well for presenters who must keep all their primary slides together. For example, conference organizers often require speakers to 'give them their presentation on a disk' so that they can dump all the slides onto a show computer. With Topical navigation, all the slides exist in a single show. So you can satisfy their need for a single set of slides, and yet still have a full array of navigation options available while performing.
