In a study dealing with the relationship between exposure to different film materials and comforting behavior, a sample of 44 college students was selected and randomly assigned to two groups. The first group was shown a film made of a new material, while the second group was shown a film made of a traditional material. After watching the films, the students were observed for comforting behavior. What is the purpose of randomly assigning the students to two groups in this study?
1) To ensure that the students in each group have similar characteristics
2) To determine the effect of exposure to different film materials on comforting behavior
3) To eliminate any bias or confounding variables that could affect the results
4) To increase the generalizability of the study findings
