$,Itempool-method {irt}

Get slots of the an Itempool-class object.

Description

Get slots of the an Itempool-class object.

Usage

## S4 method for signature 'Itempool'
x$name

Arguments

x

An Itempool-class object.

name

Name of the parameter. Available values:

'id'

Extract id's of all items and testlets. This will not extract the item_id's of items within the testlet.

'content'

Extract content's of all items and testlets. This will not extract the content's of items within the testlet.

'model'

Extract model's of all items and testlets. This will not extract the model's of items within the testlet. Use $item_model to extract models of standalone items.

'misc'

Extract misc parameters of all items and testlets. This will not extract the misc parameters of items within the testlet.

'item_list'

Extract individual elements of item pool. If there are testlets in the item pool, a testlet will be an item of the resulting list. If individual items within the testlet is desired to be elements of the list, then use $items.

'items'

Extract individual items within the item pool. If there are testlets in the item pool individual elements of the testlet will be extracted. Resulting list will only consist of Item-class objects.

'parameters'

Extract parameters's of all items and testlets. This will not extract the parameters's of items within the testlet.

'se'

Extract se's of all items and testlets. This will not extract the se's of items within the testlet.

'n'

Return a list with three objects: elements the number of standalone items and testlets. testlets the number of Testlet objects. items the sum of the number of items within testlets and standalone items.

'max_score'

Returns the maximum possible raw score of the item pool.

'item_id' or 'resp_id'

Extract item_id's of all standalone items and items within the testlets. It will not return testlet_id's. This is mainly to get the item_id's of items which has a response.

'testlet_id'

Extract testlet_id's of all items within the testlets. If the item is a standalone item, then a NA vector will be returned for it's testlet ID value.

'item_content'

Extract content's of all standalone items and items within the testlets. It will not return testlet content's. This is mainly to get the content's of items which has a response.

'item_model'

Extract model's of all standalone items and items within the testlets. It will not return testlet model's. This is mainly to get the model's of items which has a response.

'item_misc'

Extract misc fields of all standalone items and items within the testlets. It will not return testlet misc fields.

'resp_item_list'

Combine items that are not in a testlet and items within a testlet and return a list object. This list does not contain any Testlet objects. All of the elements are Item objects. If there are no testlets in the item pool, then this argument will be the same as $item_list.

'item_max_score'

Extract the maximum score each standalone item can get.

Value

See the 'name' argument above for possible return values.

Author(s)

Emre Gonulates

Examples

ip <- generate_ip(n = 7, model = "3PL", content = c("Geometry", "Algebra"))

ip$a
ip$b
ip$D
ip$model
ip$id
ip$content