Imagination is the next essential theater skill I teach.  To help develop students' imaginations, I play a similar game to the preceding concentration exercise.  I pass around the same kind of object, but this time asking the students to say not what it is, but what it might be.   Combining the concentration game with its imagination variant is an activity of real value in actually teaching social science concepts.  It's amazing what one's students can figure out about a society by concentrating closely on one artifact and using their imaginations to figure out why the object has the characteristics it does.  Northern's Dr. David Grettler is particularly good at showing students how much one can learn from close observation.  He uses in his classes everything from stone age tools, to pipe stems, to fractured bones, to cans of Coke, to Chesapeake Bay water in helping students to discover for themselves characteristics of the economy, values, and beliefs of the people they are studying.  In my own classes, I do a similar thing using slides.  For example, by having students examine closely some slides of Egyptian tomb paintings, I get them to discover a great many things about Egyptian agriculture, technology, life-style, religious beliefs, and aesthetics--and they often discover things I myself have overlooked. Other useful concentration and imagination activities include having the students describe in detail (not forgetting smells and sounds) some past event in their own lives, having students list as many of the details as they can about some historical figure or event, and having students describe in detail a scene that has been acted out in front of them.  Such exercises are particularly good for raising questions about historical epistemology.