A nursing student is reviewing a research study in which ...

[nmorano1]

A nursing student is reviewing a research study in which researchers used a pretest/posttest design to examine the effect of an AIDS education intervention on teenagers' knowledge about the condition over a school year.
 
  What threats to internal validity could be present? (Select all that apply.)
  a. Maturation
  b. Selection effects
  c. Reactivity
  d. Hawthorne effect
  e. Testing

Question 2

External validity refers to which of these issues?
 
  a. The relationship existing between the independent variable and the study outcomes
  b. The influence of a specific event on the independent variable
  c. The degree to which extraneous or mediating variables interfere with the study outcomes
  d. The degree to which findings are generalizable to populations beyond those studied

[frogdreck123456]

Answer to Question 1

ANS: A, E

Feedback
Correct Maturation could be an issue because the students may learn about AIDS from other sources over the school year.
Testing is a threat to internal validity because use of a pretest may affect subjects' subsequent responses to a posttest.
Incorrect Selection effects affect external validity or generalizability of findings.
Reactivity, or the subjects' responses to being studied, affects external validity.
The Hawthorne effect is another name for reactivity.

Answer to Question 2

ANS: D

Feedback
A Internal validity refers to the relationship between the independent variable and the study outcomes.
B Influence of a specific event (historical threat) on the study affects the dependent variable or outcome of the study. Thus it threatens internal validity and, ultimately, external validity.
C Extraneous or mediating variables are threats to internal validity because they may interfere with the treatment (independent variable) effects.
D External validity deals with possible problems of generalizability of the investigation's findings to other populations or environments.

[nmorano1]

TYSM

[elyse44]

Excellent