| ob_counter {DAKS} | R Documentation |
Computation of Numbers of Counterexamples
Description
ob_counter computes from a dataset for all item pairs the
corresponding numbers of counterexamples.
Usage
ob_counter(dataset)
Arguments
dataset |
a required data frame or matrix consisting of binary,
|
Details
For an item pair (i, j), the number of subjects solving item
j but failing to solve item i, is the corresponding
number of counterexamples. Their response patterns contradict the
interpretation of (i, j) as 'mastering item j implies
mastering item i.'
The data must contain only ones and zeros, which encode solving or failing to solve an item, respectively.
Value
If the argument dataset is of required type,
ob_counter returns a matrix of the numbers of counterexamples
for all pairs of items.
Note
The function ind_gen can be used to inductively generate from
the returned matrix of the numbers of counterexamples a set of quasi
orders.
The function iita calls ob_counter.
Author(s)
Anatol Sargin, Ali Uenlue
References
Sargin, A. and Uenlue, A. (2009) Inductive item tree analysis: Corrections, improvements, and comparisons. Mathematical Social Sciences, 58, 376–392.
Uenlue, A. and Sargin, A. (2010) DAKS: An R package for data analysis methods in knowledge space theory. Journal of Statistical Software, 37(2), 1–31. URL http://www.jstatsoft.org/v37/i02/.
See Also
ind_gen for inductive generation procedure using
numbers of counterexamples; iita, the interface that
provides the three inductive item tree analysis methods under one
umbrella. See also DAKS-package for general
information about this package.
Examples
ob_counter(pisa)