Question 1

Natalya conducted an intervention for social skills deficits. She included a group of participants in her study who did not receive any type of intervention at all. After her study finished, she took the best intervention option determined by the study and provided it to the control group. Which type of control group did Natalya use for her study?

Accepted Answer

Natalya used a waiting-list control group, which is a group of participants who do not receive the intervention during the study but are promised the intervention after the study concludes. This approach is often used in research to ethically manage control groups by eventually providing them with the intervention being tested.

Question 2

_____ is a statistical analysis that tests for differences between two or more categorical independent variables, when one is a between-subjects variable and another is a within-subjects variable.

Accepted Answer

A mixed design analysis of variance (ANOVA) is used when there are both between-subjects (independent groups) and within-subjects (same group measured at different times or under different conditions) variables in the experimental design.

Question 3

Dr. Ames conducts a mixed design ANOVA and finds the following outcome: F(1, 89) = 9.8, p = .002, eta² = .09. Which number represents the significant level?

Accepted Answer

The significant level, often denoted as p-value, indicates the probability of obtaining the observed results if the null hypothesis were true. In this case, the significant level is .002, indicating a very low probability that the observed results are due to chance, thus suggesting the results are statistically significant.

Question 4

A double-blind procedure is used in an effort to reduce the likelihood that _____ of condition will influence the results; therefore, both the participants and the administrators of treatments are unaware of which treatments are being provided.

Accepted Answer

The expectancies of condition can influence the results of an experiment, so a double-blind procedure is used to ensure neither the participants nor the administrators know which treatments are being provided, thus reducing bias.

Question 5

The experimenter-expectancy effect occurs when a bias causes a researcher to _____ the participants of an experiment.

Accepted Answer

The experimenter-expectancy effect occurs when a researcher's biases unconsciously influence the participants of an experiment, potentially affecting the outcome.

Question 6

Which of the following uses only a between-subjects methodology?

Accepted Answer

A two-group design is a type of experimental design where different participants are assigned to each of the groups being compared, which is a hallmark of between-subjects methodology. In contrast, repeated measures, mixed designs, and pretest-posttest designs involve measuring the same participants under different conditions or at different times, which are characteristics of within-subjects or mixed methodologies.

Question 7

A _____ is used when participants are unaware of, or blinded to, the treatment they are receiving, but the administrator knows which treatment each participant is getting.

Accepted Answer

A single-blind procedure is used when participants do not know which treatment they are receiving, but the researchers do. This helps to prevent participant expectations from influencing the results of the study.

Question 8

Dr. Ames conducts a mixed design ANOVA and finds the following outcome: F(1, 89) = 9.8, p = .002, eta² = .09. Which number represents the F score?

Accepted Answer

The F score in an ANOVA output is represented by the value that comes immediately after the F and its degrees of freedom notation. In this case, "F(1, 89) = 9.8" indicates that 9.8 is the F score.

Question 9

Participants in the _____ do not receive treatment or intervention until after the completion of the study.

Accepted Answer

Participants in the waiting-list control group do not receive the treatment or intervention until after the study has been completed. This approach is often used in research to control for the placebo effect and to ensure that all participants eventually receive the intervention, albeit at different times.

Question 10

Dr. Ames conducts a mixed design ANOVA and finds the following outcome: F(1, 89) = 9.8, p = .002, eta² = .09. Which number represents the effect size?

Accepted Answer

The effect size in this context is represented by eta squared (η²), which measures the proportion of the variance in the dependent variable that is attributable to the independent variable. In the given outcome, .09 is the value that represents the effect size.

Question 11

Dr. Ames conducts a mixed design ANOVA and finds the following outcome: F(1, 89) = 9.8, p = .002, eta² = .09. Which number represents the between subjects degrees of freedom?

Accepted Answer

The number that represents the between subjects degrees of freedom in an ANOVA output is the first number in the parentheses following the F statistic. In this case, it is 89.

Question 12

In a mixed design _____ of the within-subjects factor but only one level of the between-subjects factor.

Accepted Answer

In a mixed design, all participants are exposed to every level of the within-subjects factor, allowing for the measurement of how the same individuals respond to different conditions. The between-subjects factor involves different groups of participants being exposed to different conditions, but in the context of this question, it's not relevant to the answer.

Quiz 12: Mixed Design: Which Therapy Is Best for Treating Eating Disorders