com.itemanalysis.psychometrics.irt.model

Class IrmCollection

java.lang.Object

com.itemanalysis.psychometrics.irt.model.IrmCollection

All Implemented Interfaces:

java.lang.Iterable<ItemResponseModel>

public class IrmCollection
extends java.lang.Object
implements java.lang.Iterable<ItemResponseModel>

This class represents the item response models for an entire test or collection of item response models. It provides features for iterating over the item response model objects. Items may be organized into groups. ItemResponseModels are stored in an ArrayList. Group membership is stored in a Map that gives the array index of each item in a group. There is an iterator for looping over all items in the list. There is also an iterator for looping over only items within a specific group.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	IrmCollection.GroupModelIterator A class that iterates over the item response model objects for a specific group of items.

Field Summary

Fields

Modifier and Type	Field and Description
java.util.ArrayList<ItemResponseModel>	allIrm
java.util.LinkedHashMap<java.lang.String,java.util.TreeSet<java.lang.Integer>>	groupIndex

Constructor Summary

Constructors

Constructor and Description
IrmCollection()

Method Summary

Modifier and Type	Method and Description
void	addItemResponseModel(ItemResponseModel irm) Add item response models to this collection.
java.util.Iterator<java.lang.String>	getGroupNameIterator() An iterator of the group names.
java.lang.String	getID() A test or collection ID
int	getMaximumPossibleTestScore()
int	getMinimumPossibleTestScore()
int	getNumberIfItems() Number of items in the collection (i.e.
java.util.Iterator<ItemResponseModel>	groupModelIterator(java.lang.String groupID) An iterator for the item response models for a specific group of items.
java.util.Iterator<ItemResponseModel>	iterator() An iterator for all item response models in this collection (i.e.
void	removeItemResponseModel(VariableName itemToRemove) Remove an item response model.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

allIrm

public java.util.ArrayList<ItemResponseModel> allIrm

groupIndex

public java.util.LinkedHashMap<java.lang.String,java.util.TreeSet<java.lang.Integer>> groupIndex

Constructor Detail

IrmCollection

public IrmCollection()

Method Detail

addItemResponseModel

public void addItemResponseModel(ItemResponseModel irm)

Add item response models to this collection. It will also store information about the model such as the groupID and number of categories. They are stored such that the number of categories for a group is set according to the last item added to it.

Parameters:

irm -

removeItemResponseModel

public void removeItemResponseModel(VariableName itemToRemove)

Remove an item response model. It requires that everything be reset to keep accurate indices for each group.

Parameters:

itemToRemove - name of the item to be removed.

getID

public java.lang.String getID()

A test or collection ID

Returns:

the ID for this test or collection of items

getNumberIfItems

public int getNumberIfItems()

Number of items in the collection (i.e. number of items on the test).

Returns:

getMinimumPossibleTestScore

public int getMinimumPossibleTestScore()

getMaximumPossibleTestScore

public int getMaximumPossibleTestScore()

iterator

public java.util.Iterator<ItemResponseModel> iterator()

An iterator for all item response models in this collection (i.e. the test).

Specified by:

iterator in interface java.lang.Iterable<ItemResponseModel>

Returns:

an iterator

groupModelIterator

public java.util.Iterator<ItemResponseModel> groupModelIterator(java.lang.String groupID)

An iterator for the item response models for a specific group of items.

Parameters:

groupID - id for the group of items

Returns:

an iterator

getGroupNameIterator

public java.util.Iterator<java.lang.String> getGroupNameIterator()

An iterator of the group names.

Returns:

an iterator