Instructor helper: returns how a lab dataset was generated, so you can check students' conclusions. Students meet the same information in the reveal at the end of the labs.
Usage
lab_truth(data = c("certexam", "numeracy", "linking", "catbank", "openended"))Value
For "certexam", a list with the true model, the correct key,
the miskeyed item, the testlet items, the dif items and their type,
the group impact (mean ability difference in SD units), the generating
item parameters pars and the pass mark cut_raw. For "numeracy", a
list with the true model, the dif items and their type, the impact,
the generating item parameters pars (with separate values for ELL
students) and no_dif_long, long word problems without DIF. For
"linking", a list with the true model, the anchors, the drift of
the drifted anchor, each form's group ability mean and SD on the
Form A scale, the generating item parameters pars (with b_formB for
the anchors' Form B difficulties) and the Form A pass mark cut_A. For
"catbank", a list with the five over-used stars, the number of items
harder than b = 1.5 (thin_top), the student population and notes.
For "openended", a list with the true model, the severe_rater and
its severity, the inconsistent_rater, the task with a vague_rubric,
the categories to collapse, the scoring engine's bias against ELL
students (engine_bias), the group impact and the generating task
parameters pars.