Question

A 7th grade science teacher was interested in knowing if his after-school tutoring sessions would boost grades for the students in his classes. The sample consisted of all the children in his 4th and 5th hour classes. The teacher gave a pre-test to each class. Then he held twice weekly sessions for 1 hour after school for four weeks. Students required permission from their parents/guardians in order to attend. Approximately 3/4 of the students for both hours attended. At the end of the 4th week, the teacher gave a post-test and measured the gains/losses in scores. He noted a significant increase in scores and attributed those gains to his tutoring sessions.

1. Identify at least two potential threats to the validity of his study and therefore to the results.

2. Discuss the threats - how might they affect the study results?

3. Propose a method for each threat to reduce/eradicate it.

Answer 1

Answer:

(1) Potential Threats:

(I) The distinction in level of toughness  of the questions between pre-tes post - test and pre-test

(ii) The distinction in level of preparedness of understudies between post - test  and pre-test.

(2) Discussion of the threats:

(i)  If the inquiries in pre-test is simpler in pre-test than post test, the student  will score more in pre-test regardless of coaching meetings. On the off chance that the questions  in pre-test is more difficult  in pre-test than post test, the student  will score less in pre-test regardless of coaching meetings.

(ii) If the student is more ready in pre-test than post test, the student will score more in pre-test regardless of coaching meetings. In the event that the student  isn't more ready in pre-test than post test, the student will score less in pre-test regardless of coaching meetings.

(3)

(I) A strategy to eradicate or reduce  the risk of contrast in level of toughness of the inquiries between post - testand pre - test. is to see that both the and post test questions would to have a similar degree of toughness.

(ii) A technique to diminish/destroy the risk of contrast in level of preparedness of student  between post - test and pre-test is to see that both the post test and pre - test questions ought to have a similar degree of preparedness of student.