classical.c File Reference

Classical test theory. More...

#include "libirt.h"
#include <math.h>

Functions
void	classical_statistics (gsl_matrix_int *patterns, gsl_vector *items_mean, gsl_vector *items_sd, gsl_vector *items_corr, gsl_vector *items_bis_corr, gsl_vector_int *items_nbr, gsl_vector *subjects_score, gsl_vector_int *subjects_nbr, int *nbr, double *mean, double *sd, double *alpha, gsl_matrix *pairs_corr)
	Compute the classical test theory statistics.
void	classical_statistics_mc (gsl_matrix_int *patterns, gsl_vector *options_weights, gsl_vector_int *items_pos, gsl_vector_int *nbr_options, gsl_vector *items_mean, gsl_vector *items_sd, gsl_vector *items_corr, gsl_vector *items_poly_corr, gsl_vector_int *items_nbr, gsl_vector *subjects_score, gsl_vector_int *subjects_nbr, int *nbr, double *mean, double *sd, double *alpha, gsl_matrix *pairs_corr)
	Compute the classical test theory statistics.

Detailed Description

Classical test theory.

Author

Stephane Germain germs.nosp@m.te@g.nosp@m.mail..nosp@m.com

Function Documentation

void classical_statistics	(	gsl_matrix_int *	patterns,
		gsl_vector *	items_mean,
		gsl_vector *	items_sd,
		gsl_vector *	items_corr,
		gsl_vector *	items_bis_corr,
		gsl_vector_int *	items_nbr,
		gsl_vector *	subjects_score,
		gsl_vector_int *	subjects_nbr,
		int *	nbr,
		double *	mean,
		double *	sd,
		double *	alpha,
		gsl_matrix *	pairs_corr
	)

Compute the classical test theory statistics.

Parameters

[in]	patterns	A matrix(subjects x items) with the binary patterns.
[out]	items_mean	A vector(items) with the means of each items.
[out]	items_sd	A vector(items) with the sd of each items.
[out]	items_corr	A vector(items) with the correlations between each items and the score of each subject without the item.
[out]	items_bis_corr	A vector(items) with the biserial correlations between each items and the score of each subject without the item.
[out]	items_nbr	A vector(items) with the number of non missing response for each items.
[out]	subjects_score	A vector(subjects) with the scores of each subjects.
[out]	subjects_nbr	A vector(subjects) with the number of non missing response of each subjects.
[out]	nbr	The total number of non missing response.
[out]	mean	The mean score.
[out]	sd	The score sd.
[out]	alpha	The fiability coefficient alpha.
[out]	pairs_corr	A matrix(items x items) of correlation for each pair of items

Warning

The memory for the outputs should be allocated before.

void classical_statistics_mc	(	gsl_matrix_int *	patterns,
		gsl_vector *	options_weights,
		gsl_vector_int *	items_pos,
		gsl_vector_int *	nbr_options,
		gsl_vector *	items_mean,
		gsl_vector *	items_sd,
		gsl_vector *	items_corr,
		gsl_vector *	items_poly_corr,
		gsl_vector_int *	items_nbr,
		gsl_vector *	subjects_score,
		gsl_vector_int *	subjects_nbr,
		int *	nbr,
		double *	mean,
		double *	sd,
		double *	alpha,
		gsl_matrix *	pairs_corr
	)

Compute the classical test theory statistics.

Parameters

[in]	patterns	A matrix(subjects x items) with the multiple choice patterns.
[in]	options_weights	A vector(options) of weights to compute the score.
[in]	items_pos	A vector(items) with the position of the first option of each item in patterns (and probs).
[in]	nbr_options	A vector(items) with the number of option of each item in patterns (and probs).
[out]	items_mean	A vector(items) with the means of each items.
[out]	items_sd	A vector(items) with the sd of each items.
[out]	items_corr	A vector(items) with the correlations between each items and the score of each subject without the item.
[out]	items_poly_corr	A vector(items) with the polyserial correlations between each items and the score of each subject without the item.
[out]	items_nbr	A vector(items) with the number of non missing response for each items.
[out]	subjects_score	A vector(subjects) with the scores of each subjects.
[out]	subjects_nbr	A vector(subjects) with the number of non missing response of each subjects.
[out]	nbr	The total number of non missing response.
[out]	mean	The mean score.
[out]	sd	The score sd.
[out]	alpha	The fiability coefficient alpha.
[out]	pairs_corr	A matrix(items x items) of correlation for each pair of items

Warning

The memory for the outputs should be allocated before.