First, I had students come to a consensus in their groups as to what design structure they wanted to use. I had each group present their design. As each design was presented, students were asked to consider the following questions:
- Does the design answer the question of interest?
- Is there control/compare built into the design?
- Is there randomization built into the design?
- Is there replication in the design?
This was time well spent as students questioned aspects of the design and modified designs to address the questions.
There were several well-structured designs using a two-sample design and several using a matched-pair design. I then asked the students to decide how they wanted to proceed with conducting the experiment in class. The class was in favor of conducting a matched-pair design; they get more chocolate this way.
I reviewed the issues brought up during the last class as to factors that may influence the results. With those factors and the design structure in mind, I asked students to determine the experiment's procedure.
The decision was to conduct a matched-pair design using treatments of milk, semi-sweet, and dark chocolate chips. The treatment ordered would be randomly assigned to each student. The procedure is:
- Rinse mouth with water before placing chip on tongue
- Mouth to remain closed
- Tongue to remain as still as possible, with no chewing, smashing, etc.
- Subject will self-time the number of seconds for chip to melt
- Pieces will start at same temperature (room or chilled)
- Subject will wait until ready to place chip on tongue before obtaining chip
Students volunteered to bring in the chips. Next time the class will conduct the experiment.
Visit the class summary for a student's perspective and to view the lesson slides.
No comments:
Post a Comment