Parametric item banks

Parametric IRT models

High-level item banks

The high-level item banks provide shortcuts for common IRT parameterisations.

Composable item banks

The composable item banks allow flexible specification of item banks by combining different blocks to build a variety of model parameterisations.

FittedItemBanks.SlopeInterceptTransferItemBankType
struct SlopeInterceptTransferItemBank <: AbstractItemBank
SlopeInterceptTransferItemBank(distribution, difficulties, discriminations) -> SlopeInterceptTransferItemBank
DomainType(::SlopeInterceptTransferItemBank) = OneDimContinuousDomain()
ResponseType(::SlopeInterceptTransferItemBank) = BooleanResponse()

This item bank corresponds the slope-intercept form of teh 2 parameter, single dimensional IRT model.

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FittedItemBanks.TransferItemBankType
struct TransferItemBank <: AbstractItemBank
TransferItemBank(distribution, difficulties, discriminations) -> TransferItemBank
DomainType(::TransferItemBank) = OneDimContinuousDomain()
ResponseType(::TransferItemBank) = BooleanResponse()

This item bank corresponds to a 2 parameter, single dimensional IRT model.

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FittedItemBanks.CdfMirtItemBankType
struct CdfMirtItemBank <: AbstractItemBank
CdfMirtItemBank(distribution, difficulties, discriminations) -> CdfMirtItemBank
DomainType(::CdfMirtItemBank) = VectorContinuousDomain()
ResponseType(::CdfMirtItemBank) = BooleanResponse()

This item bank corresponds to the most commonly found version of MIRT in the literature. Its items feature multidimensional discriminations and its learners multidimensional abilities, but item difficulties are single-dimensional.

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FittedItemBanks.SlopeInterceptMirtItemBankType
struct SlopeInterceptMirtItemBank <: AbstractItemBank
SlopeInterceptMirtItemBank(distribution, difficulties, discriminations) -> SlopeInterceptMirtItemBank
DomainType(::SlopeInterceptMirtItemBank) = VectorContinuousDomain()
ResponseType(::SlopeInterceptMirtItemBank) = BooleanResponse()

This item bank corresponds to the slope-intercept version of MIRT in the literature. Its items feature multidimensional discriminations and its learners multidimensional abilities, but item difficulties are single-dimensional.

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FittedItemBanks.NominalItemBankType
struct NominalItemBank <: AbstractItemBank
NominalItemBank(ranks, discriminations, cut_points) -> NominalItemBank
DomainType(::NominalItemBank) = VectorContinuousDomain()
ResponseType(::NominalItemBank) = MultinomialResponse()

This item bank implements the nominal model. The Graded Partial Credit Model (GPCM) is implemented in terms of this.

Currently, this item bank only supports the normal scaled logistic as the characteristic/transfer function.

See also: GPCMItemBank (psuedo-constructor)

References:

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FittedItemBanks.MonopolyItemBankType
struct MonopolyItemBank <: AbstractItemBank
DomainType(::MonopolyItemBank) = OneDimContinuousDomain()
ResponseType(::MonopolyItemBank) = BooleanResponse()

This item bank implements the monotonic polynomial model with dichotomous responses.

\[\mathrm{irf}(\theta|\xi,{\bf b})=\xi+b_{1}\theta+b_{2}\theta^{2}+\dots+b_{2k+1}\theta^{2k+1}\]

\[\mathrm{irf}^{\prime}(\theta|\mathbf{a})=a_{0}+a_{1}\theta+a_{2}\theta^{2}+\cdot\cdot\cdot+a_{2k}\theta^{2k}\]

References:

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