Ffun: Compute the negative log likelihoods associated with a vector...

View source: R/Ffun.R

FfunR Documentation

Compute the negative log likelihoods associated with a vector of score index values.


Ffun computes the negative log likelihoods for a set of examinees, each at a single value index.


  Ffun(index, SfdList, chcemat)



A vector of size N containing values for score indices in the interval [0,100].


A numbered list object produced by a TestGardener analysis of a test. Its length is equal to the number of items in the test or questions in the scale. Each member of SfdList is a named list containing information computed during the analysis.


An N by n matrix of responses or, for a single examinee, a vector of length n.


A vector of length N of negative log likelihood values.


Juan Li and James Ramsay


Ramsay, J. O., Li J. and Wiberg, M. (2020) Full information optimal scoring. Journal of Educational and Behavioral Statistics, 45, 297-315.

Ramsay, J. O., Li J. and Wiberg, M. (2020) Better rating scale scores with information-based psychometrics. Psych, 2, 347-360.

See Also

make_dataList, index_fun, Ffun, Ffuns_plot


  #  Example 1:  Compute the values of the objective function for locating each  
  #  examinee or respondent for the 24-item short form of the SweSAT quantitative  
  #  test on the percentile score index continuum [0,100].
  #  Use only the first five examinees
  chcemat <- Quant_13B_problem_dataList$chcemat
  SfdList <- Quant_13B_problem_parmList$SfdList
  index   <- Quant_13B_problem_parmList$index
  Fval    <- Ffun(index[1:5], SfdList, chcemat[1:5,])

TestGardener documentation built on May 29, 2024, 3:31 a.m.