PSYC 301 FINAL MIDTERM QUESTIONS
correlation - Answers - a linear relationship between two continuous variables
scatterplots - Answers - used to plot correlational data
can help to see whether a linear relationship exists between two variables
correlation coefficient - Answers - a measure of the strength AND direction of a linear
relationship between two variables. represented by r
population correlation coefficient - Answers - represented by ρ (Roh)
The range of the correlation coefficient - Answers - -1 to 1
What is the correlation when r is 0? - Answers - there is no correlation
What r value(s) are associated with a small ("weak") effect - Answers - less than 0.3
What r value(s) are associated with a medium effect? - Answers - 0.3-0.499
if there is a significant correlation between two variables which possibilities should be
considered? - Answers - 1. is a cause-and-effect relationship possible?
2. Is a reverse cause-and-effect relationship possible?
3. Is it possible that the relationship is caused by a third variable or by a combination of
several other variables?
4. it is possible that the relationship may be a coincidence
Correlation _____ equal causation - Answers - does not
What is the point of a regression? - Answers - it tells us how specifically one variable
changes as the other changes
regression line (line of best fit) - Answers - A line drawn on a scatter plot to estimate
the relationship between two sets of data. The line for which the sum of squares of the
residuals is a minimum.
What is the purpose of a regression line - Answers - it is used to predict the value of y
for a given value of x
residuals - Answers - the difference between the observed y value and the predicted y
value for a given xvalue on the line. Can think of these differences as error
A positive residual is a _________ outcome - Answers - underestimated
A negative residual is a _________ outcome - Answers - overestimated
