Experimental Design Flashcards
7 cards from real FAST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Experimental Design flashcards as text
A scientist measures the same participants' anxiety levels before and after a mindfulness intervention. Which statistical concern is most relevant?
Answer: Carryover effects may confound the post-test results
In repeated-measures designs, carryover effects occur when the first condition influences performance or responses in the second condition.
Which of the following best defines 'ecological validity' in an experiment?
Answer: The degree to which results generalize to real-world settings
Ecological validity refers to how well experimental findings apply to real-world contexts beyond the laboratory.
A researcher randomly selects 200 people from a city directory and then randomly assigns them to treatment or control. Which statement is correct?
Answer: Random assignment ensures internal validity; random selection ensures external validity
Random assignment controls for confounds to establish causality (internal validity), while random selection from a population allows generalization (external validity).
What is an interaction effect in a factorial experiment?
Answer: When the effect of one independent variable differs depending on the level of another
An interaction effect occurs when the influence of one factor on the outcome depends on the level of another factor.
In experimental research, what does 'attrition' refer to and why is it a threat to validity?
Answer: Participant dropout that may systematically bias the remaining sample
Attrition (dropout) threatens internal validity if participants who leave differ systematically from those who remain, creating a biased sample.
A researcher assigns participants to groups based on their scores on a pre-test, putting the top half in Group A and the bottom half in Group B. What threat to internal validity does this introduce?
Answer: Regression to the mean affecting extreme scorers
Participants selected for extreme pre-test scores tend to score closer to the mean on post-tests regardless of treatment, a phenomenon called regression to the mean.
Which of the following correctly distinguishes a confounding variable from a mediating variable?
Answer: A confound distorts the observed relationship; a mediator explains the causal mechanism
A confounding variable is a third variable that distorts the true relationship between X and Y, while a mediator explains the causal pathway through which X affects Y.