3^rd Grade Earth Changes Unit Blueprint

Why do the results of experiments rarely turn out exactly the same?

1A(3-5)#1: Results of similar scientific investigations seldom turn out exactly the same. Sometimes this is because of unexpected differences in the things being investigated, sometimes because of unrealized differences in the methods used or in the circumstances in which the investigation is carried out, and sometimes just because of uncertainties in observations. It is not always easy to tell which.

As opportunity arises during discussion of experimental results

• Do students recognize that experimental results rarely turn out exactly the same?
• When students observe significant differences in results, do they seek possible reasons?
• Do students identify differences in methods and differences in recording/interpreting results as reasons for experimental results not being exactly the same?
• Do students support their conclusions/findings with data from experiments?
• When discussing results of experiments, do students listen to and reflect on ideas suggested by others?

Why is it important to follow directions and keep accurate records of experiments?

1B(3-5)#2: Results of similar scientific investigations are seldom exactly the same, but if the differences are large, it is important to try to figure out why. One reason for following directions carefully and for keeping records of one's work is to provide information on what might have caused the differences.

12A(3-5)#2: Offer reasons for their findings and consider reasons suggested by others.