SAGE Journal Articles
Click on the following links. Please note these will open in a new window.
It is more common for educational and psychological data to be nonnormal than to be approximately normal. This tendency may lead to bias and error in point estimates of the Pearson correlation coefficient. In a series of Monte Carlo simulations, the Pearson correlation was examined under conditions of normal and nonnormal data, and it was compared with its major alternatives, including the Spearman rank-order correlation, the bootstrap estimate, the Box–Cox transformation family, and a general normalizing transformation (i.e., rankit), as well as to various bias adjustments. Nonnormality caused the correlation coefficient to be inflated by up to +0.14, particularly when the nonnormality involved heavy-tailed distributions. Traditional bias adjustments worsened this problem, further inflating the estimate. The Spearman and rankit correlations eliminated this inflation and provided conservative estimates. Rankit also minimized the random error for most sample sizes, except for the smallest samples (n = 0.10), where bootstrapping was more effective. Overall, results justify the use of carefully chosen alternatives to the Pearson correlation when normality is violated.
Questions to Consider
1. Identify and define the differences between nonnormal and approximately normal.
Cognitive Domain: Knowledge
Difficulty Level: Medium
2. What is the significance of the distinctions between nonnormative and approximately normal, and how this tendency may lead to bias and error in point estimates of the Pearson correlation coefficient?
Cognitive Domain: Comprehension, Analysis
Difficulty Level: Medium–Hard
3. What did the authors conclude and recommend regarding alternatives to the Pearson correlation when normality is violated?
Cognitive Domain: Comprehension
Difficulty Level: Medium
Demographic heterogeneity is a central theoretical construct in organizational demography research. The most commonly used measure of demographic heterogeneity is the coefficient of variation. The author critically evaluates the rationale for using this measure and shows that the use of the coefficient of variation raises a number of methodological and interpretive problems. Empirical analyses of turnover suggest that using the coefficient of variation may lead to incorrect conclusions about the effects of demographic heterogeneity.
Questions to Consider
1. Define and discuss coefficient of variation and why this is a common theoretical construct for measuring demographic heterogeneity.
Cognitive Domain: Comprehension, Knowledge
Difficulty Level: Medium–Hard
2. The author critically evaluates the rationale for using this measure and shows that the use of the coefficient of variation raises a number of methodological and interpretive problems. Identify and discuss at least two of these problems.
Cognitive Domain: Comprehension, Analysis
Difficulty Level: Hard
3. What two cautions does the author give regarding ratio variables? What is the rationale for this caution?
Cognitive Domain: Comprehension, knowledge
Difficulty Level: Hard
Reporting p values from statistical significance tests is common in psychology’s empirical literature. Sir Ronald Fisher saw the p value as playing a useful role in knowledge development by acting as an ‘objective’ measure of inductive evidence against the null hypothesis. We review several reasons why the p value is an unobjective and inadequate measure of evidence when statistically testing hypotheses. A common theme throughout many of these reasons is that p values exaggerate the evidence against H0. This, in turn, calls into question the validity of much published work based on comparatively small, including 0.05, p values. Indeed, if researchers were fully informed about the limitations of the p value as a measure of evidence, this inferential index could not possibly enjoy its ongoing ubiquity. Replication with extension research focusing on sample statistics, effect sizes, and their confidence intervals is a better vehicle for reliable knowledge development than using p values. Fisher would also have agreed with the need for replication research.
Questions to Consider
1. Discuss and explain what the authors offer regarding reasons why the p value is an unobjective and inadequate measure of evidence when statistically testing hypotheses.
Cognitive Domain: Comprehension
Difficulty Level: Medium
2. Why do the authors believe that p values exaggerate the evidence against H0?
Cognitive Domain: Comprehension, Analysis
Difficulty Level: Medium–Hard
3. What is the significance of the p value as an unobjective and inadequate measure of evidence as it relates to published studies? Do you see potential concerns regarding validity?
Cognitive Domain: Comprehension
Difficulty Level: Hard
If sex drive is a generalized energizer of sexual behaviors, then high sex drive should increase an individual’s sexual attraction to both men and women. If sex drive energizes only dominant sexual responses, however, then high sex drive should selectively increase attraction to men or to women, but not to both, depending on the individual’s sexual orientation. Data from three studies assessing a total of 3,645 participants show that for most women, high sex drive is associated with increased sexual attraction to both men and women. For men, however, high sex drive is associated with increased sexual attraction to only one sex or the other, depending on the individual’s sexual orientation. These results suggest that the correlates of sex drive and the organization of sexual orientation are different for women and men.
Questions to Consider
1. Why did the authors compute correlation coefficients? Why could not they use the two-way chi-square from Chapter 6 of your textbook?
Learning Objective: Pearson’s correlation coefficient
Cognitive Domain: Application
Difficulty Level: Medium
2. The authors report among heterosexual men that sex drive was correlated .23 to attraction to women and that attraction to men was correlated –.49 with attraction to women. Which relationship is stronger? (a) Sex drive and attraction to women. (b) Sex drive and attraction to men. (c) Attraction to men and attraction to women. (d) Not enough information to determine.
Learning Objective: Pearson’s correlation coefficient
Cognitive Domain: Comprehension
Difficulty Level: Easy
3. According to your power analysis table in your textbook, which group had an adequate power to detect a small effect size? (a) Heterosexual men. (b) Heterosexual women. (c) Gay men. (d) Lesbian women.
Learning Objective: Power
Cognitive Domain: Knowledge
Difficulty Level: Hard
Although empowering leadership is generally considered to be a desirable leadership approach, its effectiveness has been questioned and the response is mixed. Integrating the “Too-Much-of-a-Good-Thing” effect and dual task processing, this study examines the relationship between empowering leadership and task performance. Specifically, we suggest a curvilinear relationship between empowering leadership and employee task performance. Further, applying a leadership contingency perspective, we propose that the curvilinear relationship between empowering leadership and employee task performance is moderated by employee learning orientation. Using survey data from 137 supervisor–subordinate dyads, our results show that the inverted U-shaped relationship between empowering leadership and employee task performance is moderated by employee learning orientation. Theoretical and practical implications are discussed.
Questions to Consider
1. The authors report a correlation of 0.33 between empowering leadership and task performance. Is this a good estimate of the relationship between these two variables? Explain why or why not.
Cognitive Domain: Analysis
Difficulty Level: Medium
2. If the authors were concerned that they had range restriction in measuring education, this might mean: (a) they are misrepresenting the correlations with education, (b) the full range of educational values was not captured, (c) the correlations with education are probably smaller than they should be, (d) all of the above.
Cognitive Domain: Synthesis
Difficulty Level: Medium
3. What is the magnitude of the relationship between LMX and empowering leadership: (a) Small. (b) Medium. (c) Large. (d) Undeterminable.
Cognitive Domain: Comprehension
Difficulty Level: Easy