Generic interface

abstract type AbstractItemBank

Base supertype for all item banks.

struct ItemResponse{ItemBankT<:AbstractItemBank}

• item_bank::AbstractItemBank

• index::Int64

An item response.

abstract type DomainType

DomainType(::AbstractItemBank) -> DomainType

Domain type for a item banks' item response functions. Used as a trait.

abstract type DiscreteDomain <: DomainType

A discrete domain. Typically this is a sampled version of a continuous domain item bank.

Item response functions with discrete domains tend to support less operations than those with continuous domains.

abstract type ContinuousDomain <: DomainType

A continuous domain.

struct VectorContinuousDomain <: ContinuousDomain

A continuous domain that is vector valued.

struct OneDimContinuousDomain <: ContinuousDomain

A continuous domain that is scalar valued.

struct DiscreteIndexableDomain <: DiscreteDomain

An discrete domain which is efficiently indexable and iterable.

struct DiscreteIterableDomain <: DiscreteDomain

An discrete domain which is only efficiently iterable.

abstract type ResponseType

ResponseType(::AbstractItemBank) -> ResponseType

A response type for an item bank. Used as a trait.

struct BooleanResponse <: ResponseType

A boolean/dichotomous response.

struct MultinomialResponse <: ResponseType

A multinomial response, including ordinal responses.

length(item_bank::AbstractItemBank)

Returns the number of items in the item bank.

function subset(item_bank::AbstractItemBank, idxs)

Return a new item bank of the same type, with the items at the given indices.

function subset_view(item_bank::AbstractItemBank, idxs)

Similar to above, but allow the usage of views.

item_bank_domain(
    item_bank::AbstractItemBank;
    zero_symmetric,
    items,
    thresh
) -> Tuple{Any, Any}

Given an item bank, this function returns the domain of the item bank, i.e. the range (lo, hi) which includes for each item the range in which the the item response function is changing.

eachindex(item_bank::AbstractItemBank) -> Base.OneTo

Returns an AbstractUnitRange of item indices for the item bank.

item_params(item_bank::AbstractItemBank, idx) -> NamedTuple

Returns the raw parameters for the item at idx as a named tuple. This may return nothing for some item banks. This is debugging/informational use only. Use (ItemResponse)[@ref] for actual item response functions.

resp(ir::ItemResponse, θ) -> Float64  # For BooleanResponse item banks only
resp(ir::ItemResponse, outcome, θ) -> Float64

Return the value of the item response outcome function for the item response ir, the outcome outcome and the ability values θ. For BooleanResponse item banks, outcome can be omitted in which case the outcome is assumed to be true.

resp_vec(ir::ItemResponse, θ) -> AbstractVector{Float64}

Return the vector value of the item response function for the item response ir, the outcome outcome and the ability values θ.

The outcome at each index corresponds with the indices returned by the responses function.

responses(ir::ItemResponse) -> Any

Returns an AbstractVector of possible outcomes for a given (ItemResponse)[@ref].