com.itemanalysis.psychometrics.polycor

Class PearsonCorrelation

java.lang.Object

com.itemanalysis.psychometrics.polycor.PearsonCorrelation

All Implemented Interfaces:

java.lang.Comparable<PearsonCorrelation>

public class PearsonCorrelation
extends java.lang.Object
implements java.lang.Comparable<PearsonCorrelation>

This class is mainly a short-cut for the Pearson correlation. The same computations are provided in Covariance.java with the exception of the correctedValue() method. This method is only found here and it is used primarily for correcting a correlation for spuriousness for an item analysis.

Author:

J. Patrick Meyer

Constructor Summary

Constructors

Constructor and Description
PearsonCorrelation()
PearsonCorrelation(boolean unbiased)

Method Summary

Modifier and Type	Method and Description
int	compareTo(PearsonCorrelation that)
java.lang.Double	correctedValue() Correct correlation for spuriousness.
boolean	equals(java.lang.Object obj)
int	hashCode()
void	increment(java.lang.Double X, java.lang.Double Y)
double	sampleSize()
double	value()
double	value(boolean unbiased)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PearsonCorrelation

public PearsonCorrelation(boolean unbiased)

PearsonCorrelation

public PearsonCorrelation()

Method Detail

increment

public void increment(java.lang.Double X,
                      java.lang.Double Y)

correctedValue

public java.lang.Double correctedValue()

Correct correlation for spuriousness. This method assumes that the test item is Y and the test score is X. Used for the point-biserial and biserial correlation in an item analysis.

Returns:

correlation corrected for spuriousness

value

public double value()

value

public double value(boolean unbiased)

sampleSize

public double sampleSize()

compareTo

public int compareTo(PearsonCorrelation that)

Specified by:

compareTo in interface java.lang.Comparable<PearsonCorrelation>

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object