plotPWmap {eRm}  R Documentation 
A BondandFox Pathway Map displays the location of each item or each person against its infit tstatistic. Pathway maps are useful for identifying misfitting items or misfitting persons. Items or people should ideally have a infit tstatistic lying between about 2 and +2, and these values are marked.
plotPWmap(object, pmap = FALSE, imap=TRUE,
item.subset = "all", person.subset = "all",
mainitem = "Item Map", mainperson = "Person Map",
mainboth="Item/Person Map",
latdim = "Latent Dimension",
tlab = "Infit t statistic",
pp = NULL, cex.gen = 0.6, cex.pch=1,
person.pch = 1, item.pch = 16,
personCI = NULL, itemCI = NULL, horiz=FALSE)
object 
Object of class 
pmap 
Plot a person map if 
imap 
Plot an item map if 
item.subset 
Subset of items to be plotted for an item map.
Either a numeric vector indicating the item numbers or a character
vector indicating the item names. If 
person.subset 
Subset of persons to be plotted for a person map.
Either a numeric vector indicating the person numbers or a character
vector indicating the person names. If 
mainitem 
Main title of an item plot. 
mainperson 
Main title of a person plot. 
mainboth 
Main title of a person/item joint plot. 
latdim 
Label of the yaxis, i.e., the latent dimension. 
tlab 
Label of the xaxis, i.e., the tstatistic dimension. 
pp 
If non 
cex.gen 

cex.pch 
applies to all plotting symbols. The default is 1. 
person.pch, item.pch 
Specifies the symbol used for plotting
person data and item data respectively; the defaults are 1 and 16
respectively. See 
personCI, itemCI 
Plotting confidence intervals for the the
person abilities and item difficulties. If The same goes for 
horiz 
if 
This code uses vertical(horizontal) error bars rather than circles or boxes to indicate standard errors. It also offers the possibility of plotting item or person data on its own; this can considerably simplify the reading of the plots for large datasets.
Julian Gilbey
Bond T.G., Fox C.M. (2007) Applying the Rasch Model: Fundamental Measurement in the Human Sciences (2nd ed.) chapter 3, Lawrence Erlbaum Associates, Inc.
Linacre J.M., Wright B.D. (1994) Dichotomous Infit and Outfit MeanSquare Fit Statistics / ChiSquare Fit Statistics. Rasch Measurement Transactions 8:2 p. 350, https://www.rasch.org/rmt/rmt82a.htm
Linacre J.M. (2002) What do Infit and Outfit, Meansquare and Standardized mean? Rasch Measurement Transactions 16:2 p. 878, https://www.rasch.org/rmt/rmt162f.htm
Wright B.D., Masters G.N. (1990) Computation of OUTFIT and INFIT Statistics. Rasch Measurement Transactions 3:4 p. 84–85, https://www.rasch.org/rmt/rmt34e.htm
res < PCM(pcmdat)
pparm < person.parameter(res)
plotPWmap(res, pp = pparm)
plotPWmap(res, pp = pparm, pmap = TRUE)