A study is said to have internal validity if the researcher can ...

[burchfield96]

A study is said to have internal validity if the researcher can be relatively confident that ____.
 
  a. the same results would occur if the experiment were replicated
  b. changes in the independent variable caused changes in the dependent variable
  c. the operational definitions used in the study were chosen well
  d. the sample was representative of the broader population of interest

Question 2

Suppose that, at your 60th high school reunion, you gather together the senior portraits and relate your classmates' facial expressions to their mortality rates. Based on the study of baseball players, what would you expect to find?
 
  a. Facial expressions in the portraits were unrelated to mortality rates.
  b. Students with big smiles and those with half smiles lived longer than those who did not smile at all, but those with big and half smiles had similar lifespans.
  c. Students who frowned had very short lifespans while those who smiled even a little had average life spans.
  d. Students with big smiles had the longest lifespans, followed by those with partial smiles, and then by those with no smiles.

[whitcassie]

Answer to Question 1

B

Answer to Question 2

D

[burchfield96]

Excellent

[matt95]

TYSM