Exam 11: Moderation, Mediation and More Regression

Imagine we found a strong positive correlation between worry and sleep disturbances and we hypothesized that drinking caffeine before going to bed would exacerbate this relationship. What type of analysis could we conduct to test this hypothesis?

Imagine we found that drinking caffeine before going to bed significantly moderates the relationship between worry and sleep disturbances. What does this tell us?

Imagine we conducted a mediation analysis and obtained a kappa-squared value of .8 for the indirect effect. What does this tell us?

Mediation has occurred when:

How do we test for moderation?

Imagine it was found that worry explains the relationship between depression and sleep problems (i.e., depressed people tend to worry more than non-depressed people, leading them to experience more sleep problems). Which of the following is the indirect effect?

A researcher had a categorical variable that they wanted to include as a predictor in a regression equation. The researcher was trying to predict the success of a back pain intervention, and the categorical variable was the duration of the back pain prior to treatment, with 4 categories: less than 6 months, 6-12 months, 1-2 years, more than 2 years. They needed to code these variables into dummy variables for the regression using less than 6 months as their control category. Which of the following represents the correct coding scheme?

Imagine we wanted to investigate whether a person's profession can predict scores on a self-report psychopathy scale. We collected data from people in eight professions and a group of unemployed people. The eight professions were: bank traders, insurance brokers, health care professionals, business executives, volunteer workers, full-time mums, teachers, construction workers. The outcome was psychopathy score. How could we analyse these data?

Which of the following sentences best describes mediation?

Imagine we found a strong positive correlation between depression and sleep problems. We might hypothesize that this relationship is explained by worry (i.e., depressed people tend to worry more than non-depressed people, leading them to experience more sleep problems). What type of analysis could we conduct to test this hypothesis?

Which of the following is an example of perfect mediation?

An experiment was done to look at whether different relaxation techniques could predict sleep quality better than nothing. A sample of 400 participants were randomly allocated to one of four groups: massage, hot bath, reading or nothing. For one month each participant received the same relaxation technique for 30 minutes before going to bed each night. A special device was attached to the participant's wrist that recorded their quality of sleep, providing them with a score out of 100. The outcome was the average quality of sleep score over the course of the month. -Which of the following tables displays the most appropriate coding scheme for analysing these data?

Imagine we wanted to look at predictors of popularity of famous sports people. We might hypothesize that the type of sport played would predict how popular the sports person was. Imagine we recruited 1000 participants and asked them to rate out of 10 (10 = They are the best sports person in the world, 0 = They are the worst sports person in the world) how much they liked 100 famous sports people from 10 different types of sports (10 sports people from each category). Could we analyse these data using regression, and if so how?

Why is it common in moderation analysis to transform the predictors using grand mean centring?

Which of the following sentences about grand mean centring in moderation analysis is not true?

A busy social life has been found to increase happiness in participants who are experiencing low levels of stress, but decrease happiness in participants who are experiencing high levels of stress. What is this an example of?

Imagine we wanted to investigate whether a person's profession can predict scores on a self-report psychopathy scale. We collected data from people in eight different professions and a group of unemployed people. The eight professions were: bank traders, insurance brokers, health care professionals, business executives, volunteer workers, full-time mums, teachers, construction workers. The outcome was psychopathy score. If we wanted to analyse these data using regression, how many dummy variables would we need?

A simple slopes analysis:

Which of the following is not one of Baron and Kenny's four conditions of mediation?

An experiment was done to look at whether different relaxation techniques could predict sleep quality better than nothing. A sample of 400 participants were randomly allocated to one of four groups: massage, hot bath, reading or nothing. For one month each participant received the same relaxation technique for 30 minutes before going to bed each night. A special device was attached to the participant's wrist that recorded their quality of sleep, providing them with a score out of 100. The outcome was the average quality of sleep score over the course of the month. - Which test could we use to analyse these data?