itemfit.ppar {eRm} | R Documentation |
pmat
computes the expected person-item matrix with corresponding
probabilities. residuals
computes the squared and standardized residuals based on
the observed and the expected person-item matrix. Chi-square based itemfit and personfit
statistics can be obtained by using itemfit
and personfit
.
## S3 method for class 'ppar': pmat(object) ## S3 method for class 'ppar': itemfit(object) ## S3 method for class 'ppar': personfit(object) ## S3 method for class 'ppar': residuals(object,...) ## S3 method for class 'ifit': print(x, ...) ## S3 method for class 'pfit': print(x, ...)
object |
Object of class ppar , derived from person.parameter . |
x |
Object of class ifit , pfit , or resid . |
... |
Further arguments passed to or from other methods. They are ignored in this function. |
Function pmat
:
pmat |
Matrix of theoretical probabilities. |
i.fit |
Itemfit statistics. |
i.df |
Degrees of freedom for itemfit statistics. |
st.res |
Standardized residuals. |
p.fit |
Personfit. |
p.df |
Degrees of freedom for personfit statistics. |
st.res |
Standardized residuals. |
Patrick Mair, Reinhold Hatzinger
Smith Jr., E. V., and Smith, R. M. (2004). Introduction to Rasch Measurement. JAM press.
# Rasch model, estimation of item and person parameters data(raschdat2) res <- RM(raschdat2) p.res <- person.parameter(res) # Matrix with expected probabilities and corresponding residuals pmat(p.res) residuals(p.res) #Itemfit itemfit(p.res) #Personfit personfit(p.res)