Exam 3: Correlation and Regression
Assume that X and Y correlate .4, are in Z score form, and that a particular value of X is 1. What is the predicted value of Y ?
B
Describe the difference between correlation and regression. What are the advantages and disadvantages of each method of assessing bivariate relationships?
Correlation and regression are both statistical methods used to assess the relationship between two variables. However, they have different purposes and provide different types of information.
Correlation measures the strength and direction of the relationship between two variables. It ranges from -1 to 1, with 1 indicating a perfect positive relationship, -1 indicating a perfect negative relationship, and 0 indicating no relationship. Correlation does not imply causation, meaning that just because two variables are correlated does not mean that one causes the other.
On the other hand, regression is used to predict the value of one variable based on the value of another variable. It provides information about the strength and direction of the relationship, as well as the ability to make predictions. Regression can also be used to test hypotheses about the relationship between variables.
The advantages of correlation include its simplicity and ease of interpretation. It provides a clear indication of the strength and direction of the relationship between variables. However, correlation does not provide information about the ability to predict one variable based on the other.
The advantages of regression include its ability to make predictions and test hypotheses about the relationship between variables. It provides more detailed information about the relationship and allows for the identification of potential causal relationships. However, regression can be more complex and may require more assumptions about the data.
The disadvantages of correlation include its inability to make predictions and its lack of information about causation. It also does not provide information about the ability to predict one variable based on the other.
The disadvantages of regression include its complexity and the potential for overfitting the data. It also requires more assumptions about the data and may be more difficult to interpret for those without a strong statistical background.
In summary, correlation and regression are both valuable methods for assessing bivariate relationships, but they provide different types of information and have different strengths and limitations. The choice of method depends on the specific research question and the goals of the analysis.
If the line that comes closest to all points in a scatter diagram is perfectly straight, the correlation between the two variables is
If the correlation between X and Y is .60 and we observe a score of 1.0 ( Z units)on X , what score would be predicted for Y ?
A regression equation was derived from a small sample in which X and Y are correlated .6. The equation is Y ´ = .6 X + 15. Suppose this equation were applied to a second sample. It is likely that the correlation between the scores predicted from this equation and the observed scores will be
Owning a dog may make people happier. Then again, happier people may be more likely to want a dog. Not knowing whether happiness leads to dog ownership or vice versa, we have
Which of the following is computed to show the relationship between two artificially dichotomous variables?
Which of the following is an artificially dichotomous variable?
The best-fitting straight line through a set of points in a scatter diagram is known as the
One formula for the correlation between a continuous variable and an artificially dichotomized variable is
The sum of the squared deviations around the mean will be ______ it is around any value other than the mean.
Which of the following correlations represents the strongest relationship between two variables?
An appropriate correlation coefficient to show the relationship between two artificially dichotomous variables is the
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