IM1-14
5. If you rejected the hypothesis, how would you refine and rewrite your hypothesis to
account for your findings and begin again?
Exercise 5: Data Collection and Interobserver Error (30 to 45 minutes)
For this exercise, you will need to provide students with four different objects to measure (e.g., a
piece of printer paper, a brand-new pencil, a dry-erase marker, and a paper clip). If you have a
small class, you may be able to use the same four objects and pass them around to each student
to measure. If you have a large class (or you want to speed up the activity), you can break your
class into small groups and give each group their own set of objects to measure.
You will also need to provide students with the same measuring implements, such as tape
measures, rulers, or measuring sticks. It is important that you give everyone in the class (or
everyone in each small group) the same measuring tool. For example, if one student is given a
foot-long wooden ruler, everyone should be given the same kind of ruler. This will limit errors
introduced by differences among measuring devices. If you do not have enough of the same
measuring tool for each student, you may have them all share, or you may give each small group
their own measuring tool to use and share.
[Note: The raw data will vary depending on the objects measured, but the general responses
about differences noted and possible causes for them should be as follows.]
STEP 1: Collect the data.