An experimenter predicts that a behavior modification program ...

[oliviahorn72]

An experimenter predicts that a behavior modification program will shorten the length of stay in an institution for retarded adolescents. The null hypothesis would be _____.
 
  a. the behavior modification program will not shorten the length of stay in the institution
  b. the behavior modification program will not lengthen the length of stay in the institution
  c. the behavior modification program will not affect the length of stay in the institution
  d. all of these are correct

Question 2

An experimenter uses the pretest posttest design to test the effectiveness of a new drug in reducing joint pain. The null hypothesis would state that _____.
 
  a. affects hallucinations
  b. increases hallucinations
  c. the new drug does reduce hallucinations
  d. decreases joint pain

[meganlapinski]

Answer to Question 1

A
The alternative hypothesis is directional. Therefore, the effect is to shorten the length of stay in the institution. The null hypothesis states that the treatment (the behavior modification program) does not cause the effect (shorten the length of stay).

Answer to Question 2

C
The null hypothesis states that the treatment (the new drug) does not cause the effect (reduce hallucinations.

[oliviahorn72]

Wow, this really help

[amcvicar]

Excellent