Introduction

This document contains basic technical information about the DRDP(2015)’s measures in the five essential domains of readiness:

  1. Approaches to Learning/Self-Regulation (ATLREG)
  2. Social and Emotional Development (SED)
  3. Language and Literacy Development (LLD)
  4. Cognition (COG)
  5. Physical Development/Health (PDHLTH)

The information presented here consists of selected measurement model diagnostics related to the DRDP(2015)’s measures. Some background in item response modeling and familiarity with the DRDP(2015)’s measures is assumed. The measurement model is a Rasch unidimensional partial credit model. The latent variables for the five essential domains of readiness were aligned to a single measurement scale using dimensional alignment. For more technical details about the DRDP assessment system, see https://www.desiredresults.us/research. For additional details about dimensional alignment, see https://doi.org/10.1177/01466216211013103.

Each Section Contains

  • Item Characteristic Curves (modeled curves only)
  • Item Fit Graphs (mean item difficulty vs. item infit or outfit)

Data Source

The results are based on data from a random sample of 100,000 children with DRDP scores for all 5 essential domains of readiness. (n: Infant/Toddler = 14773, Preschool = 83903, Kindergarten = 1364). The results from kindergarten levels and K-only item PDHLTH6 should be intepreted with appropriate caution, given the relatively smaller sample size of kindergarteners.

ATLREG

Modeled Item Characteristic Curves

The curves show the probability of being in a certain category (see legend at right), given the child’s estimated score, represented as a greek theta. There were no disordered categories in the results.

Item Fit Graphs

Graphs show the item mean difficulty on the vertical axis and the mean square fit statistic (outfit or infit) on the horizontal axis. The misfit convention of 0.75/1.33 is used.

SED

Modeled Item Characteristic Curves

The curves show the probability of being in a certain category (see legend at right), given the child’s estimated score, represented as a greek theta. There were no disordered categories in the results.

Item Fit Graphs

Graphs show the item mean difficulty on the vertical axis and the mean square fit statistic (outfit or infit) on the horizontal axis. The misfit convention of 0.75/1.33 is used. Better than expected fit is not considered problematic.

LLD

Modeled Item Characteristic Curves

The curves show the probability of being in a certain category (see legend at right), given the child’s estimated score, represented as a greek theta. There were no disordered categories in the results.

Item Fit Graphs

Graphs show the item mean difficulty on the vertical axis and the mean square fit statistic (outfit or infit) on the horizontal axis. The misfit convention of 0.75/1.33 is used. Better than expected fit is not considered problematic.

COG

Modeled Item Characteristic Curves

The curves show the probability of being in a certain category (see legend at right), given the child’s estimated score, represented as a greek theta. There were no disordered categories in the results.

Item Fit Graphs

Graphs show the item mean difficulty on the vertical axis and the mean square fit statistic (outfit or infit) on the horizontal axis. The misfit convention of 0.75/1.33 is used. Better than expected fit is not considered problematic.

PDHLTH

Modeled Item Characteristic Curves

The curves show the probability of being in a certain category (see legend at right), given the child’s estimated score, represented as a greek theta. There were no disordered categories in the results.

Item Fit Graphs

Graphs show the item mean difficulty on the vertical axis and the mean square fit statistic (outfit or infit) on the horizontal axis. The misfit convention of 0.75/1.33 is used.