APA Research Methods and Statistics 1 — Questions and Answers
Question 1: Which research design allows researchers to establish cause-and-effect relationships between variables?
- Correlational study
- Case study
- True experiment (Correct answer)
- Naturalistic observation
Correct answer: True experiment
True experiments use random assignment and manipulation of an independent variable, which is the only design that allows causal conclusions.
Question 2: In APA-style reporting, what does a p-value of .03 indicate?
- There is a 3% probability the effect is real
- There is a 3% probability the results occurred by chance if H₀ is true (Correct answer)
- The effect size is small
- The hypothesis was accepted
Correct answer: There is a 3% probability the results occurred by chance if H₀ is true
A p-value of .03 means there is a 3% probability of obtaining results at least as extreme as observed if the null hypothesis were true.
Question 3: Which measure of central tendency is most affected by extreme outliers?
- Mode
- Median
- Mean (Correct answer)
- Range
Correct answer: Mean
The mean uses every data point in its calculation, so extreme outliers can substantially pull it in their direction.
Question 4: What is the purpose of a double-blind procedure in experimental research?
- To prevent participants from withdrawing
- To ensure anonymity of data
- To reduce demand characteristics and experimenter bias (Correct answer)
- To match participants on key variables
Correct answer: To reduce demand characteristics and experimenter bias
In a double-blind study, neither participants nor researchers who interact with them know group assignments, reducing bias from both sides.
Question 5: According to APA guidelines, which correlation coefficient magnitude is typically considered 'large'?
- .10
- .30
- .50
- .70 or above (Correct answer)
Correct answer: .70 or above
Cohen's conventions define a large correlation as r ≥ .50, with many researchers treating .70+ as clearly large.
Question 6: What is 'informed consent' as required by APA ethical standards?
- Consent obtained after debriefing
- Voluntary agreement to participate after being told about the study's nature and risks (Correct answer)
- Parental permission for adult participants
- Written approval from an IRB
Correct answer: Voluntary agreement to participate after being told about the study's nature and risks
Informed consent requires that participants voluntarily agree to participate after being provided adequate information about the study's purpose, procedures, and risks.
APA Research Methods and Statistics 1
Which research design allows researchers to establish cause-and-effect relationships between variables?