LSP Research Methods & Statistics — Questions and Answers
Question 1: What is the difference between a correlational study and an experimental study?
- Correlational studies measure relationships between variables without manipulation; experimental studies manipulate an independent variable to determine causation (Correct answer)
- They are identical in design
- Correlational studies are always more rigorous
- Experimental studies never use statistical analysis
Correct answer: Correlational studies measure relationships between variables without manipulation; experimental studies manipulate an independent variable to determine causation
Correlational designs measure the strength and direction of relationships between variables but cannot establish causation. Experimental designs manipulate independent variables and use controls to establish cause-and-effect relationships.
Question 2: What is a p-value in statistical analysis?
- The probability of obtaining results at least as extreme as those observed, assuming the null hypothesis is true (Correct answer)
- The percentage of participants who completed the study
- The power of the statistical test
- The proportion of variance explained
Correct answer: The probability of obtaining results at least as extreme as those observed, assuming the null hypothesis is true
A p-value less than the significance level (typically 0.05) indicates the results are unlikely to have occurred by chance alone, leading researchers to reject the null hypothesis.
Question 3: What is random assignment and why is it important in experiments?
- Randomly placing participants into experimental and control groups to ensure groups are equivalent at baseline (Correct answer)
- Choosing participants randomly from the population
- Assigning random numbers to data points
- Randomizing the order of test questions
Correct answer: Randomly placing participants into experimental and control groups to ensure groups are equivalent at baseline
Random assignment ensures each participant has an equal chance of being in any condition, distributing potential confounding variables evenly across groups and increasing internal validity.
Question 4: What is the difference between Type I and Type II errors?
- Type I is rejecting a true null hypothesis (false positive); Type II is failing to reject a false null hypothesis (false negative) (Correct answer)
- They are the same error
- Type I errors are more serious than Type II errors in all cases
- These errors only occur in correlational research
Correct answer: Type I is rejecting a true null hypothesis (false positive); Type II is failing to reject a false null hypothesis (false negative)
A Type I error (alpha) occurs when you conclude there is an effect when there is not. A Type II error (beta) occurs when you conclude there is no effect when there actually is one.
Question 5: What is a meta-analysis?
- A statistical technique that combines results from multiple studies to derive an overall effect size (Correct answer)
- A single large-scale experiment
- A type of qualitative research
- A method of analyzing individual case studies
Correct answer: A statistical technique that combines results from multiple studies to derive an overall effect size
Meta-analysis quantitatively synthesizes findings from multiple independent studies on the same topic, providing a more precise estimate of effect size and identifying moderating variables across studies.
Question 6: What is informed consent in research?
- Ensuring participants understand the study's purpose, procedures, risks, benefits, and their right to withdraw before agreeing to participate (Correct answer)
- Getting participants to sign any form
- Informing participants of results after the study
- Obtaining consent from the participant's employer
Correct answer: Ensuring participants understand the study's purpose, procedures, risks, benefits, and their right to withdraw before agreeing to participate
Research informed consent requires clear disclosure of the study's nature, potential risks and benefits, confidentiality protections, compensation if any, and the participant's absolute right to withdraw at any time without penalty.
LSP Research Methods & Statistics
What is the difference between a correlational study and an experimental study?