fit_joint_gaze_rt_irt: Joint response, response-time, and gaze-process IRT

In eyeprocess: Harmonize Eye-Tracking, Pupillometry, Biometrics, and Psychometric Process Data

Joint response, response-time, and gaze-process IRT

Description

The reference engine fits crossed person/item submodels for accuracy, log-response-time, and a gaze process, then returns person- and item-side latent-score covariance summaries. The 'brms' engine uses multivariate formulas with shared group-level IDs so person/item random effects can be correlated across channels.

Usage

fit_joint_gaze_rt_irt(
  data,
  response = "response",
  rt = "rt",
  gaze = "fixation_count",
  person = "participant_id",
  item = "item_id",
  gaze_family = c("negative_binomial", "poisson"),
  engine = c("reference", "brms"),
  iter = 2000,
  chains = 4,
  cores = 1,
  seed = 1,
  ...
)

Arguments

data	Long person-by-item data.
response	Binary response variable.
rt	Positive response-time variable.
gaze	Gaze process variable, usually fixation count or dwell count.
person, item	Person and item identifiers.
gaze_family	Poisson or negative-binomial reference channel.
engine	'reference' or 'brms'.
iter, chains, cores	Passed to brms.
seed	Random seed.
...	Additional arguments to the selected engine.

Value

An 'eye_joint_gaze_rt_irt' object.

eyeprocess documentation built on Sept. 28, 2026, 5:08 p.m.