Science Buddies: "Ask an Expert"

I am working on the experiment Shaping Your Thoughts. I do have a concern though. This experiment doesn't seem to have a control group but my teacher told me all experiments have a control group and an experimental group. Does this experiment need a control group or can each volunteer just do the (4) tests?

Hello,

In this experiment, I believe (although hopefully I can have another expert confirm this) that the control group would be the group where the shapes have the correct names written on them, and each of the other three groups is a variation. Each volunteer still takes the four tests. Please let me know if this makes sense.

Thanks.