When students don't understand the experiment

Some students (and they may be the majority of the class) do not understand why they

  • set the starting position of the lower link at the 0” mark,
  • mark the starting position of the upper link,
  • move the lower link 1”, 2” and 3”
  • measure the segment of the upper link between the marker and the edge of the base, and
  • record the number in the data table.

Understanding may come by going through these steps, then examining the data. Try the following alternative procedure.

  • Students do experiment A. The class looks for patterns in the data and at the same time decides which numbers are most likely to be right.
  • Students then change the position of the output link and do experiment B. Again the class looks for patterns in the data.

 

As students discuss their data, include questions about how measurements were made when the measurements look wrong (i.e., where the output does not move twice the input in Experiment A or three times the input in Experiment B.)

As students discuss their data, include questions about how measurements were made when the measurements look wrong (i.e., where the output does not move twice the input in Experiment A or three times the input in Experiment B.)

Now give out new data sheets and let students repeat Experiments A and B. Students will understand the purpose and procedures of the experiments much more clearly when they repeat them. At this point they are ready to do Experiments C and D.


Unit Lessons