Does anyone see a value in putting a full sentence instead of just a title on a PowerPoint slide for classroom training? For example, The Second Step in the Cycle is Employee Maintenance vs. Step 2 in the Cycle.

How about, "Step 2: Employee Maintenance"? Full sentences are a little cumbersome. I don't see the need. There are so many other techniques to get the point across - including visuals.

I'm with Kal as far as what the title in words could be for the slide example you provided.

To me, the point of PowerPoint is to make powerful *points* visually; not give people giant text to read.

If you are publishing a "table of contents" of the presentation by listing slide titles (and clearly if you are handing out the slides), and there are a lot of slides, you may want to go with
Employee Maintenance vs Step 2
Employee Maintenance and oil changes
Employee Maintenance and tire changes

If there are such topics spread throughout the notes. This makes finding the right page easy. Multiple slides entitled Employee Maintenance makes finding slides hard (it also does for the author/presenter). Of course, if they are all in a section on Employee Maintenance, you could title them differently ("... and Oil Changes" or whatever).

Otherwise I agree with KaliKo and FF.