For instance, you might want to add two buttons on a slide. The buttons are intended for two different audiences. If the student were to click button 1, a previously hidden text caption would appear; if the student were to click button 2, a previously hidden button might appear offering all kinds of potential branching scenarios... the options are quite literally endless.
Forcing an object to be invisible by default is simple. Show the Properties of the object and, on the Options tab, deselect the Visible check box.
At this point, it would also be a good idea to give the object a name--you can use this name should you decide Advanced Actions later or use the object as part of a multi-action button.
If you were to preview the project at this point, any items that you've rendered invisible won't appear--and they won't publish. Nice! Of course, if you actually want the hidden objects to appear, you've got a few choices. First, you can create an Advanced Action (via Project > Actions) that would force the hidden object to appear after other events have occurred on the slide. What's that you say? You don't know how to create Actions? No worries... let's move to plan B: create a button or click box on the slide and attach multiple actions (one of the actions would be to force a hidden object to appear).
To attach multiple actions to an object, show its Properties. Select Multiple actions from the On success drop-down menu and then click the Browse button.
The Set Multiple Actions dialog box will appear. Select the Action you need from the actions listed in the Available actions column, select the object you want from the list of available objects at the bottom of the dialog box and click the Add button.
And here's the beauty of multiple actions: if you wanted something else to happen on the slide as a result of the single click on the object (maybe you want something visible on the slide to disappear as the previously hidden object appears), you could select a second action (such as the Hide action), pick a slide object and click the Add button.
When finished, click OK to close the Set Multiple Actions dialog box and the Properties dialog box. Then preview the project to test the multiple actions.