Testlet-class {irt}

An S4 class to represent a Testlet

Description

Testlet is a class to represent an a collection of items. Items that are connected by a common stimulus (for example a reading passage, a graph, etc.) can form a testlet. An object in Testlet class should have a model name and item_list which is an Itempool. object. In fact, a Testlet object is very similar to an Itempool-class object, except, it has a designated model and optional parameters.

Slots

testlet_id

Testlet ID. Default value is NULL.

item_list

A list of Item objects.

model

The model that testlet parameters represents. Currently model can be: BTM (Basic Testlet Model, this is default testlet model where no parameters necessary and testlet simply connects items), RTM (Rasch Testlet Model), BF (Bifactor Model) (Not implemented yet), 2PTM (Two-parameter testlet model), 3PTM (three-parameter testlet model). A model must be specified for the construction of an tetlet object.

parameters

A list containing numeric vectors that represent testlet parameters. Depending on the model these parameters can change.

se_parameters

Standard error of testlet parameters.

content

Content information for testlet.

misc

A list of additional parameters for the testlet.

Author(s)

Emre Gonulates