Exam 15: Correlation

A computer analysis that essentially calculates the average of every possible split-half correlation as a measure of reliability is known as:

In a re-analysis of published studies, Twenge and Im (2007) found that for the time period 1958-2001, the need for social approval of people in the United States was negatively correlated with the U.S.divorce rate during the same period (the correlation coefficient was -0.38).This correlation means that:

If two variables are correlated, it means that they are causally related in some way.

When performing a hypothesis test for correlation, one tests the research hypothesis that $\rho$ = 1.0.

If one wishes to assess the relation between a farming county's average annual temperature and the crop yield, it may be important to take into account the overlapping variability that crop yield and temperature share with rainfall.To do so, one would compute a:

According to guidelines published by Cohen (1988), a correlation value of -0.48 would be considered:

If all the points on a scatterplot fall on a single line:

In a re-analysis of published studies, Twenge and Im (2007) found that for the time period 1958-2001, the need for social approval of people in the United States was negatively correlated with the U.S.violent crime rate during the same period (the correlation coefficient was -0.31).This correlation means that:

In an investigation of the psychometric properties of the Criminal Sentiments Scale (CSS), Witte et al.(2006) administered the scale to 72 sex offenders.They found that scores on the scale correlated positively with recidivism for nonsexual crimes, but not for sexual crimes.This research suggests that the CSS is:

Which of these is NOT an assumption when conducting hypothesis testing for r?

A Pearson correlation coefficient is calculated for 48 individuals.What value of df should be used to determine statistical significance in hypothesis testing?

One assumption for using hypothesis testing for Pearson correlation is that one variable should vary equally at each level of the other variable.What is the easiest way to determine whether this assumption has been met?

If a positive relation exists between two variables, then low scores on one variable will be associated with _____ scores on the other variable.

A coefficient alpha of _____ is considered a minimally acceptable level of reliability for measures that will be used to make decisions about individuals based on their scores on the measure.

Tysha notices that every time she wears jewelry to work she has a very productive day and finishes all her projects on time.When she doesn't wear jewelry she struggles to get everything done.She concludes that wearing jewelry is the cause for her successful days at work and buys more jewelry.Is she correct?

The strength or size of a correlation coefficient is independent of its sign.

A technique that quantifies the degree of association between two variables after statistically removing the association of a third variable with both of those two variables is:

What kind of correlation would one expect to find between the severity of snowstorms and rates of attendance at college classes?

Every day for the last month, Boris has recorded the number of times it has rained and the height of all of his tomato plants.He wants to see if the two are correlated, so he creates a scatterplot of the data.He sees a pattern that he could probably draw a line through (from the bottom left going up to the top right) as rainy days and plant height both increase.What type of correlation is this?

According to guidelines published by Cohen (1988), a correlation value of -0.09 would be considered: