CORRELATION & PEARSON Flashcards
a statistical technique that is used to measure and
describe the relationship between two variables
Correlation
The corresponding correlation for the entire population is identified
by the Greek letter
rho (ρ)
the Greek equivalent of the letter r
rho (ρ)
The sign of the correlation, positive or negative, describes the direction of the relationship
The Direction of the Relationship
Some relationships tend to have a linear form; the points in the scatter plot tend to cluster around a straight line.
The Form of the Relationship
most common use of correlation is to
measure _ relationships
straight-line relationships (The Form of the Relationship)
in correlation other forms of relationships do exist and there are _ correlations used to measure them.
special correlations (The Form of the Relationship)
The correlation measures the consistency of the relationship.
The Strength or Consistency of the Relationship
for a linear relationship the data points could fit perfectly on a _ line
straight line(The Strength or Consistency of the Relationship)
Every time X increases by one point, the value of Y also changes by a _ and predictable amount.
consistent (The Strength or Consistency of the Relationship)
- The Direction of the Relationship
- The Form of the Relationship
- The Strength or Consistency of the Relationship
3 characteristics of a relationship
- perfect negative correlation, –1.00,
- no linear trend, 0.00,
- a strong positive relationship, approximately +.90
- a relatively weak negative correlation,
approximately –0.40
different values for linear
correlations
a perfect negative correlation, have a value of
–1.00
no linear trend, have a value of
0
a strong positive relationship, approximately have a value of
0.9
a relatively weak negative correlation, approximately have a value of
–0.40
measures the degree and the direction of the linear relationship between two variables
Pearson correlation
used to measure the amount of covariability between two variables.
The Sum of Products of Deviations
- Prediction
- Validity
- Reliability
- Theory Verification
Where and Why Correlation Are Used
If two variables are known to be related in some systematic way, it is possible to use one of the variables to make accurate predictions about the other.
Prediction
If two _ are known to be related in some systematic way, it is
possible to use one of the variables to make accurate predictions
about the other.
variables
One common technique for demonstrating validity is to use a
correlation.
Validity
If a test actually measures intelligence, then the scores on the test should be related to other measures of intelligence—for example, standardized IQ tests, performance on learning tasks, problem-solving ability
Validity
One way to evaluate reliability is to use correlations to determine the relationship between two sets of measurements
Reliability
When reliability is high, the correlation between two measurements
should be strong and positive
Reliability
One way to evaluate reliability is to use _ to determine the relationship between two sets of measurements
correlations
When reliability is _, the correlation between two measurements
should be strong and positive
high
The prediction of the theory could be tested by determining the correlation between the two variables.
* Well-being and positivity
* Rumination and depression
Theory Verification
The prediction of the _ could be tested by determining the
correlation between the two variables
Theory