Our Ideas

The key question for this activity is:

How can you tell when a supporting reason for a conclusion is good or poor?

1. 1. Based on what you learned in this activity, work with your partner to write your answer to the key question.

Use what you learned in this activity and How To Evaluate an Experiment Conclusion to decide if the two conclusions below are valid or not valid. You can assume that the experiment is a fair test and that these two students had access to the class data table.

Record your answers and reasons after discussing them with your partner. Follow the same approach used by Rebecca and Chantel.

1. 2. Carlos wrote the following conclusion and reason: Conclusion: We conclude that there is no relationship between magnet size and strength. Reason: Our medium-sized magnet and our largest magnet both pulled the paper clip from the same distance away. Is the conclusion valid or not valid? Explain.
2. 3. Nguyen wrote the following conclusion and reason: Conclusion: We conclude that when magnet size increases, its strength increases.Reason: We know that larger objects are stronger than smaller objects. Is the conclusion valid or not valid? Explain. Participate in a class discussion about your answers.