CDM (version 1.0-0)

summary.din: Summary Method for Objects of Class din

Description

S3 method to summarize objects of the class din.

Usage

## S3 method for class 'din':
summary(object, \dots)

Arguments

object

a required object of class din, obtained from a call to the function din.

...

Optional parameters to be passed to or from other methods will be ignored.

Value

• If the argument object is of required type, summary.din returns a named list, of the class summary.din, consisting of the following five components:
• CALL
  a character specifying the model rule, the number of items and the number of attributes underlying the items.
• IDI
  a matrix giving the diagnostic accuracy for each item $j$ $$IDI_j = 1 - \frac{g_j}{1-s_j},$$ where high diagnostic accuracy corresponds to good test items which have both low guessing and slipping rates. Note that a negative diagnostic accuracy in one item contradicts the error parameter constraint $g_j < 1 - s_j$. See din for help.
• SKILL.CLASS.PROB
  a table which returns the minimum, maximum, quantile and mean information of the skill pattern distribution.
• AIC
  a numeric giving the AIC of the specified model object.
• BIC
  a numeric giving the BIC of the specified model object.

Details

The function summary.din returns an object of the class summary.din (see Value), for which a print method, print.summary.din, is provided. Specific summary information details such as individual item parameters and their diagnostic accuracy can be accessed through assignment (see Examples).

References

Rupp, A. A., Templin, J. L. and Henson, R. A. (2010) Diagnostic Measurement: Theory, Methods, and Applications. New York: The Guilford Press.

See Also

plot.din, the S3 method for plotting objects of the class din; print.din, the S3 method for printing objects of the class din; summary.din, the S3 method for summarizing objects of the class din, which creates objects of the class summary.din; din, the main function for DINA and DINO parameter estimation, which creates objects of the class din. See also CDM-package for general information about this package.

Examples

##
## (1) examples based on dataset fractions.subtraction.data
## 

## Parameter estimation of DINA model
# rule = "DINA" is default
fractions.dina <- din(data = fraction.subtraction.data,
  q.matrix = fraction.subtraction.qmatrix, rule = "DINA")
  
## corresponding summaries, including diagnostic accuracies,
## summary of skill pattern distribution and information 
## criteria AIC and BIC
summary(fractions.dina)

## In particular, accessing detailed summary through assignment
detailed.summary.fs <- summary(fractions.dina)
str(detailed.summary.fs)