Exam 9: Regression

A medical researcher was interested in examining what factors influenced patient's scores in a fitness test. He ran a multiple linear regression, which included four predictors ('hours spent taking part in physical activity per day', 'calories consumed per day', 'BMI', and 'hours spent sitting per day'). His model had a R² of .665, an adjusted R² of .661, an F-statistic of 112.56 (p 0.00). How would you interpret his findings?

A consumer researcher was interested in what factors influence people's fear responses to horror films. She measured gender and how much a person is prone to believe in things that are not real (fantasy proneness). Fear responses were measured too. In this table, what does the value 847.685 represent? $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$ ANOVA $^ { a }$ Model Sum of Squares Mean Square Sig. 1 Regression 103.457 1 103.457 9.419 .00 Residual 900.675 82 10.984 Total 1004.132 83 2 Regression 156.448 2 78.224 7.475 .00 Residual 847.685 81 10.465 Total 1004.132 83 a. Dependent Variable: Fear after Horror Film b. Predictors: (Constant), Gender c. Predictors: (Constant), Gender, Fantasy Proneness

What does the graph below show?

The following graph shows:

Which of the following is a means to cross-validate your model?

A psychologist was interested in whether the amount of news people watch (minutes per day) predicts how depressed they are (from 0 = not depressed to 7 = very depressed). What does the standardized beta tell us in the output?

Why is multicollinearity a potential problem in a multiple linear regression?

Recent research has shown that lecturers are among the most stressed workers. A researcher wanted to know exactly what it was about being a lecturer that created this stress and subsequent burnout. She recruited 75 lecturers and administered several questionnaires that measured: Burnout (high score = burnt out), Perceived Control (high score = low perceived control), Coping Ability (high score = low ability to cope with stress), Stress from Teaching (high score = teaching creates a lot of stress for the person), Stress from Research (high score = research creates a lot of stress for the person), and Stress from Providing Pastoral Care (high score = providing pastoral care creates a lot of stress for the person). The outcome of interest was burnout, and Cooper's (1988) model of stress indicates that perceived control and coping style are important predictors of this variable. The remaining predictors were measured to see the unique contribution of different aspects of a lecturer's work to their burnout. -What does the scatterplot show?

Which of the following statements about the F-ratio is true?

A psychologist was interested in whether the amount of news people watch predicts how depressed they are. In this table, what does the value 4.404 represent? $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$ ANOVA $^{a}$ Model Sum of Squares df Mean Square F Sig. 1 Regression 3.030 1 3.030 4.404 .03 Residual 57.115 83 .688 Total 60.145 84 a. Dependent Variable: Depression b. Predictors: (Constant), News Exposure

Recent research has shown that lecturers are among the most stressed workers. A researcher wanted to know exactly what it was about being a lecturer that created this stress and subsequent burnout. She recruited 75 lecturers and administered several questionnaires that measured: Burnout (high score = burnt out), Perceived Control (high score = low perceived control), Coping Ability (high score = low ability to cope with stress), Stress from Teaching (high score = teaching creates a lot of stress for the person), Stress from Research (high score = research creates a lot of stress for the person), and Stress from Providing Pastoral Care (high score = providing pastoral care creates a lot of stress for the person). The outcome of interest was burnout, and Cooper's (1988) model of stress indicates that perceived control and coping style are important predictors of this variable. The remaining predictors were measured to see the unique contribution of different aspects of a lecturer's work to their burnout. -Which of the predictor variables does not predict burnout?

Which of the following are potential sources of bias in a linear model?

A psychologist was interested in predicting how depressed people are from the amount of news they watch. Based on the output, do you think the psychologist will end up with a model that can be generalized beyond the sample?

What is cross-validation?

Recent research has shown that lecturers are among the most stressed workers. A researcher wanted to know exactly what it was about being a lecturer that created this stress and subsequent burnout. She recruited 75 lecturers and administered several questionnaires that measured: Burnout (high score = burnt out), Perceived Control (high score = low perceived control), Coping Ability (high score = low ability to cope with stress), Stress from Teaching (high score = teaching creates a lot of stress for the person), Stress from Research (high score = research creates a lot of stress for the person), and Stress from Providing Pastoral Care (high score = providing pastoral care creates a lot of stress for the person). The outcome of interest was burnout, and Cooper's (1988) model of stress indicates that perceived control and coping style are important predictors of this variable. The remaining predictors were measured to see the unique contribution of different aspects of a lecturer's work to their burnout. -How would you interpret the beta value for 'stress from teaching'?

A researcher was interested in examining what factors influenced children's scores in a fitness test. He ran a multiple linear regression, which included four predictors ('hours spent taking part in physical activity per day', 'calories consumed per day', 'BMI', and 'hours spent watching TV per day'). His model had a R² of .665, an adjusted R² of .661, an F-statistic of 112.56 (p 0.00). How would you interpret his findings

R² is:

Why is bootstrapping a good way to ensure robust confidence intervals and significance values?

A consumer researcher was interested in what factors influence people's fear responses to horror films. She measured gender (0 = female, 1 = male) and how much a person is prone to believe in things that are not real (fantasy proneness) on a scale from 0 to 4 (0 = not at all fantasy prone, 4 = very fantasy prone). Fear responses were measured on a scale from 0 (not at all scared) to 15 (the most scared I have ever felt). What is the likely population value of the parameter describing the relationship between gender and fear?

Recent research has shown that lecturers are among the most stressed workers. A researcher wanted to know exactly what it was about being a lecturer that created this stress and subsequent burnout. She recruited 75 lecturers and administered several questionnaires that measured: Burnout (high score = burnt out), Perceived Control (high score = low perceived control), Coping Ability (high score = low ability to cope with stress), Stress from Teaching (high score = teaching creates a lot of stress for the person), Stress from Research (high score = research creates a lot of stress for the person), and Stress from Providing Pastoral Care (high score = providing pastoral care creates a lot of stress for the person). The outcome of interest was burnout, and Cooper's (1988) model of stress indicates that perceived control and coping style are important predictors of this variable. The remaining predictors were measured to see the unique contribution of different aspects of a lecturer's work to their burnout. -Which of the predictor variables does not predict burnout?