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Correlation and Regression- - Coggle Diagram
Correlation and Regression-
A linear relationship
is how well the data points fit a straight line by a Pearson correlation.
The Sum of Products of Deviations-is
a statistical quantity that shows up in correlation, covariance, and regression. It measures how two variables vary together
Pearson correlation
measures the degree and the direction of the linear relationship between two variables. The Pearson correlation for a sample is identified by the letter r.
Definitional formula
-The definitional formula for the sum of products of deviations expresses how two variables vary together by comparing each value to its mean.
computational formula
-The computational formula for the sum of products of deviations provides a faster way to calculate the same quantity without explicitly finding each deviation from the mean
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Validity
refers to the degree to which a measurement, test, or research study actually measures what it claims to measure.
Prediction-
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.
Theory Verification.
-involves gathering data, conducting observations or experiments, and analyzing results to determine whether the predictions derived from the theory actually occur in the real world.
Reliability
-refers to the consistency, stability, and repeatability of a measurement, test, or instrument
Correlation and Causation
Causation,
on the other hand, means that one variable directly produces a change in another.
An outlier
is an individual with X and/or Y values that are substantially different (larger or smaller) from the values obtained for the other individuals in the data set.
Correlation and restricted range
refer to the weakening or distortion of a correlation coefficient when the variability of one or both variables is limited.
A restricted range
can lead to underestimation of the strength of a relationship, mask real correlations, or sometimes even change the direction of the correlation.
The Hypotheses
formal statements that propose a relationship between variables and guide the investigation.-
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Correlation
refers to a statistical association between two variables, when one changes, the other tends to change as well
Correlation matrix
is a table that shows the correlation coefficients between multiple variables in a dataset. It allows you to quickly see how each variable is related to every other variable.