Experimentation Nation!
A study splits participants into two groups: one listens to music, and the other sits in silence. What kind of variable is the group assignment?
What is an independent variable?
What rule of causality ensures that the cause comes before the effect?
What is temporal precedence?
A researcher gives preschoolers a math test intended for high school students. Most of the preschoolers score zero. What is this issue called?
What is a floor effect?
A study examines the effects of teaching style (lecture vs. group work) and time of day (morning vs. evening) on test performance. What type of design is this?
Hint: The answer has numbers
What is a 2×2 factorial design?
A researcher keeps both participants and data collectors unaware of group assignments. What type of study is this?
What is a double-blind study?
When an experiment includes participants experiencing all levels of the independent variable, what type of design is this?
What is a within-groups design?
What is the term for uncontrolled factors that might explain the results of a study instead of the intended variables?
What are confounding variables?
A study finds no difference between two treatments, but this result occurs because the sample size was too small. What is this outcome called?
What is a null result?
In a 3×2 factorial design, how many independent variables are there?
What is two?
In a study on weight loss, participants in the control group are given a sugar pill instead of the actual supplement. What is this process called?
What is a placebo?
Assigning participants to groups based on rolling a die is an example of what experimental procedure?
What is random assignment?
What type of threat occurs when participants drop out of a study, causing uneven groups?
What is attrition?
When measuring a new therapy's effect, the participants’ scores are all very low, making differences between groups hard to detect. What is this issue called?
What is a floor effect?
In a factorial design, what does it mean if one line on a graph is flat while another line slopes upward?
What is a spreading interaction?
A researcher who carefully calibrates all equipment before every test session is addressing which potential threat to validity?
What is instrumentation?
A study compares participants taught multiplication by reading a textbook, watching a video, or having an instructor. What is this an example of?
What is a between-groups design?
A study on the effects of sleep deprivation is disrupted when a power outage affects the sleep schedule of half the participants. What threat is this?
What is a history threat?
A researcher finds that the confidence interval for the effect of a new drug does not include zero. What can they conclude?
What is the effect is statistically significant?
A researcher examines two independent variables, each with three levels. How many unique conditions exist?
What is nine?
Observers unconsciously record more favorable data for the experimental group because they expect better results. What is this?
What is observer bias?
A researcher uses a within-groups design to measure memory before and after listening to music. What type of variable is the "before and after" measure?
What is a repeated measure?
Researchers in a study fail to control the temperature of the testing room, which causes participants to perform differently depending on their discomfort level. What is this an example of?
What is situation noise?
A researcher tests two groups and finds they perform equally well because the test is too easy for both. What type of effect occurred?
What is a ceiling effect?
A researcher studying meal timing (morning vs. evening) and exercise type (cardio vs. strength) finds both variables independently influence energy levels. What is this result?
What is two main effects?
A researcher uses a placebo in their study to prevent participants from altering their behavior based on expectations. What threat does this address?
What are demand characteristics?
A study introduces a manipulation check to confirm whether participants experienced the intended mood. What is this check addressing?
What is construct validity?
A study finds that students do better on a posttest than a pretest, but the improvement is due to familiarity with the test format. What threat is this?
What is a testing threat?
A researcher conducts an experiment and finds a significant main effect but no significant interaction. What does this mean?
What is the independent variable affected the outcome, but the effect did not depend on another variable?
In a study on exercise and mood, researchers find that the improvement in mood from exercise is much greater for people with low initial fitness levels compared to those with high fitness levels. What is this result called?
What is a difference of differences?
Name three disadvantages of within-groups designs.
**This will be on the exam!!!**
(a) Within-groups designs have the potential for order effects;
(b) they have an increased risk for demand characteristics;
(c) it may not be realistic to have participants provide repeated measures;
(d) it may be impossible for participants to experience something twice (as in the example from the textbook of learning to ride a bike twice).