ty_policies: Compare routing and scoring policies

In throughyear: Linking, Routing and Fairness for Through-Year Assessment

Compare routing and scoring policies

Description

Administers the MST under five policies to the same examinees:

cold

Full routing module, population prior for routing and scoring.

prior_route

Full routing module, student's interim prior for routing only; population prior for the reported score.

prior_both

Interim prior for routing and for the reported score.

prior_short

Interim prior for routing with a shortened routing module ('short_n' items); population prior for scoring.

prior_only

Route on the interim prior alone (no routing module); population prior for scoring.

Usage

ty_policies(mst, theta, prior, population = NULL, short_n = 6, seed = NULL)

Arguments

mst	A 'ty_mst'.
theta	True summative abilities.
prior	Student priors ('mean', 'sd') from 'predict()' on a 'ty_link'.
population	Population prior 'c(mean, sd)'; default: moments of the student priors' implied marginal.
short_n	Routing items for 'prior_short'.
seed	Optional seed (each policy gets its own stream).

Value

A 'ty_policies' object: named list of [ty_administer()] results, plus 'theta'.

Examples

sim <- ty_simulate(n_calibration = 300, n_operational = 300, seed = 1)
op <- sim[sim$cohort == "operational", ]
prior <- predict(ty_link(sim), op)
pol <- ty_policies(ty_mst_default(), op$theta_S, prior, seed = 1)
summary(pol)

throughyear documentation built on Oct. 8, 2026, 5:07 p.m.