CDM (version 2.7-7)

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, top.n.skill.classes = 6, 
     log.file = NULL, overwrite = FALSE, \dots)

Arguments

object

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

top.n.skill.classes

A numeric, specifying the number of skill classes, starting with the most frequent, to be returned. Default value is 6.

log.file

An optional character vector, specifying the directory and/or filename to which an extensive summary output should be written.

overwrite

An optional boolean, specifying wether or not the method is supposed to overwrite an existing log.file. If the log.file exists and overwrite is FALSE, the user is asked to confirm the o

...

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 seven 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 item discrimination index (IDI; Lee, de la Torre & Park, 2012) for each item $j$ $$IDI_j = 1 - s_j - g_j ,$$ where a high IDI corresponds to favorable test items which have both low guessing and slipping rates.
• SKILL.CLASSES
  A vector giving the top.n.skill.classes most frequent skill classes and the corresponding class probability.
• AIC
  A numeric giving the AIC of the specified model object.
• BIC
  A numeric giving the BIC of the specified model object.
• log.file
  A character giving the path and file of a specified log file.
• din.object
  The object of class din for which the summary was requested.

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 discrimination indices can be accessed through assignment (see Examples).

References

Lee, Y.-S., de la Torre, J., & Park, Y. S. (2012). Relationships between cognitive diagnosis, CTT, and IRT indices: An empirical investigation. Asia Pacific Educational Research, 13, 333-345. Rupp, A. A., Templin, J. L., & 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,
## most frequent skill classes 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)