STATISTICS MODULE 7
CORRELATIONAL ANALYSIS AND
LINEAR REGRESSION 2026/27
___ is performed to measure and describe how two quantitative variables are related
- ANSWER-Correlational analysis
Correlational analysis is performed when variables are observed in their ___ rather
than being manipulated in a study - ANSWER-observed in their natural state
___ describes the direction of a relationship, form of a relationship (linear,
curvilinear, quadratic, or cubic), and the degree of a relationship. - ANSWER-
Correlation
___ describes the direction of the linear relationship between two variables -
ANSWER-Covariance
If two variables covary, one of two directions exist in the plot of variables:
1.
2. - ANSWER-1. Both variables increase or decrease together.
OR
2. As one variable increases the other decreases
Covariance does not imply __ - ANSWER-Covariance does not imply causation
___ is a limitation of correlational studies, however, correlation being established is
the first step in determining ___ - ANSWER-Causation, causality
The most common ways correlations are represented graphically are with ___, a
graph in which two measurements are obtained from each individual in the study and
paired variable scores are plotted as coordinate pairs. - ANSWER-scatterplots
In scatterplots, the independent variable is on the ___ and the dependent variable is
on the __ - ANSWER-In scatterplots, the independent variable is on the x-axis and
the dependent variable is on the y-axis.
In scatterplots, the independent variable is called the ___ and the dependent
variable is called the __ - ANSWER-explanatory, response
A linear relationship describes when plotted pairs ___ - ANSWER-approximate a
straight line
A positive correlation indicates - ANSWER-that both variables are increasing
together
, A negative correlation indicates - ANSWER-that an increase in the explanatory
variable results in a decrease in response variables
As the r-values move closer to +1 and -1, the points resemble ___ - ANSWER-
straight lines
___ results in smaller correlation coefficients and inaccurate relationship measures
between two variables - ANSWER-Range restriction
True/False:
Correlational analysis is not impacted by outliers - ANSWER-False, correlational
analysis is impacted by outliers
___ is a correlation coefficient that is calculated to determine the degree and
direction of the relationship between X and Y if a linear relationship exists. -
ANSWER-Pearson's r
No correlation indicates - ANSWER-There is no relationship between two variables,
on a scatterplot points are spread out and do not resemble a straight line.
When values of two variables appear to be related, but the relationship does not
follow a linear pattern, this is called a ___ relationship - ANSWER-nonlinear or
curvilinear relationship (for example exponential relationship)
The ___, Pearson's r, measures the degree of linear relationship or consistency of
the relationship - ANSWER-correlation coefficient
r = -1 indicates - ANSWER-perfect negative relationship, perfectly inverse
relationship between x and y
r=0 indicates - ANSWER-no correlation
r = +1 indicates - ANSWER-perfectly positive relationship between x and y
Researchers typically look for a correlation coefficient of what values before
considering a relationship between two variables? - ANSWER-r<-0.05 or r>0.05
r =0.7 to 0.9 indicates a - ANSWER-high correlation
r= 0.5 to 0.7 indicates - ANSWER-moderate correlation
r=0.3 to 0.5 indicates - ANSWER-low positive correlation
r=0.0 to 0.3 indicates - ANSWER-very weak or negligible correlation
Pearson's r is a sample statistic, whereas __ is the population parameter -
ANSWER-ρ "rho"