updateStats: Recalculates statistics for changed student model.

In ralmond/EABN: Evidence Accumulation Bayes Net Engine

Recalculates statistics for changed student model.

Description

When the student model of a StudentRecord changes, because the function updateSM has been run, the statistics need to be recalculated. The function updateStats recalculates the statistics. The function announceStats lets the listeners know that new statistics are available for this user.

Usage

updateStats(eng, rec, debug = 0)
announceStats(eng, rec)

Arguments

eng	A BNEngine controlling the operation.
rec	A StudentRecord, particularly, one that has just been updated via a call to updateSM.
debug	An integer flag. If the value is greater than 1, there will be a call recover inside of the call.

Details

The BNEngine contains a number of Statistic objects. Every time the student model (sm) of the StudentRecord changes, the stats of the record need to be updated as well.

The function updateStats simply loops through the statistic collection and calculates the new values. The corresponding field of the student record is then updated.

The function announceStats takes the new statistic values and generates a P4Message containing the new statistics. This is sent to all of the Listener objects in the ListenerSet attached to the engine.

The function stats returns the latest statistics from the student record.

Value

The function updateStats returns the updates StudentRecord object.

The function announceStats is called for its side effects. Its return value should not be used.

Author(s)

Russell Almond

References

Almond, Mislevy, Steinberg, Yan and Williamson (2015). Bayesian Networks in Educational Assessment. Springer. Especially Chapters 5 and 13.

See Also

Classes: BNEngine, ListenerSet StudentRecord, Statistic, P4Message

Functions in EABN: accumulateEvidence, updateHist, updateSM, stats

Peanut Functions: calcStat

Proc4Functions notifyListeners

Examples

## Requires PNetica
library(PNetica)  ## Must load to setup Netica DLL
app <- "ecd://epls.coe.fsu.edu/EITest"
sess <- RNetica::NeticaSession()
RNetica::startSession(sess)

config.dir <- file.path(library(help="Peanut")$path, "auxdata")
net.dir <- file.path(library(help="PNetica")$path,"testnets")

netman <- read.csv(file.path(config.dir, "Mini-PP-Nets.csv"),
                    row.names=1, stringsAsFactors=FALSE)
stattab <- read.csv(file.path(config.dir, "Mini-PP-Statistics.csv"),
                    as.is=TRUE)

Nethouse <- PNetica::BNWarehouse(netman,session=sess,
             address=net.dir)

cl <- new("CaptureListener")
listeners <- list("cl"=cl)

ls <- ListenerSet(sender= paste("EAEngine[",app,"]"),
                  db=MongoDB(noMongo=TRUE), listeners=listeners)

eng <- newBNEngineNDB(app=app,warehouse=Nethouse,
                     listenerSet=ls,manifest=netman,
                     profModel="miniPP_CM",
                     histNodes="Physics",
                     statmat=stattab,
                     activeTest="EAActive.txt")

## Standard initialization methods.                     
loadManifest(eng,netman)
eng$setHistNodes("Physics")
configStats(eng,stattab)
setupDefaultSR(eng)

sr0 <- getRecordForUser(eng,"S1")

eap0 <- stat(sr0,"Physics_EAP")

e1 <- EvidenceSet(uid="S1",app="Test",context="PPcompEM",
                  obs=list("CompensatoryObs"="Right"))


sr1 <- updateRecord(sr0,e1)
sr1 <- updateSM(eng,sr1,e1)
sr1 <- updateStats(eng,sr1)
eap1 <- stat(sr1,"Physics_EAP")

## This should have changed.
stopifnot(abs(eap1-eap0) > .001)

announceStats(eng,sr1)
## Look at the resulting message.
cl$lastMessage()
details(cl$lastMessage())
stopifnot(uid(cl$lastMessage())=="S1",context(cl$lastMessage())=="PPcompEM")

ralmond/EABN documentation built on Aug. 30, 2023, 12:52 p.m.