What is the structuralist perspective?

Chris would like to conduct a study on the effectiveness of a new substance-abuse treatment program. he has a sample of participants go through the program and he uses as a comparison group people who did not volunteer for the program but were eligible. chris has used a(n) design for his study.

Mr. mann's science students were experimenting with speed. they set up a 1 meter (100 cm) track. the students used balls instead of cars. the balls were different sizes and made of different materials. four at a time, students rolled balls around the track to see which had the fastest and slowest speeds. some of their data are shown in the table. which ball will take the longest to complete one lap around the track?

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