Stephen B asked:
It depends on whether you are using conference room or ballroom style. In conference room style, your slides are delivered only in handout form, and therefore you should have only one slide per handout. In ballroom style, if you give a handout, I would design it as a conference room style slide, and then hand it out at the end, switch off the projector and take your audience through it as a brief conference room style presentation.
That said, one of the advantages of a conference room style slide is that it will contain much more information than your typical ballroom style slide. Research shows that when more steps in your logic are shown together on one slide, audiences understand your argument better. (It makes sense: if they can see everything at the same time, then they do not have to rely on their memory of what you said on previous slides to put the argument together).
Because of this, newcomers to conference room style will sometimes just combine a number of traditional slides into a "four-square," something like this example.
But a conference room style slide is not complete unless it passes the squint test. To pass the squint test, the layout of the slide must tell us something about what is going on on the slide.
If we squint at the first slide here, all we see is four charts. There is no indication of how the charts relate to each other. Certainly, it is better than having each chart on a different slide, but that is not enough.
What we need to do is design the slide so that the overall layout tells us–instantly–what is happening on the page. In the second slide, we can see that the three charts together conclude into a set of recommendations. The whole story is now on one page, and therefore it is easier to understand. Of course, this is a conference room style slide and therefore it should only be delivered in print form–as a handout–and never projected on a screen (the type font is too small for projection).
Conference room style slides are radical departure from what we are used to. However, they are far more effective when presenting to small audiences. So try it, and turn off the projector.