A Supplemental Information About Assessment Design and Development

A.1 Differential Item Functioning Plots

The plots in this section display the best-fitting regression line for each gender group, with jittered plots representing the total linkage levels mastered for individuals in each gender group. Plots are labeled with the item ID, and only items with non-negligible effect-size changes are included. The results from the uniform and combined logistic regression models are presented separately. For a full description of the analysis, see the Evaluation of Item-Level Bias section.

A.1.1 Uniform Model

These plots show items that had a non-negligible effect-size change when comparing \(M_1\) to \(M_0\). In this model, the probability of a correct response was modeled as a function of ability and gender.

The plot of the uniform race differential item function evidence for Science item 49044. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis. The plot of the uniform race differential item function evidence for Science item 50121. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis. The plot of the uniform race differential item function evidence for Science item 55919. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis.

A.1.2 Combined Model

These plots show items that had a non-negligible effect-size change when comparing \(M_2\) to \(M_0\). In this model, the probability of a correct response was modeled as a function of ability, gender, and their interaction.

The plot of the combined gender differential item function evidence for Science item 50095. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis. The plot of the combined gender differential item function evidence for Science item 70791. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis. The plot of the combined race differential item function evidence for Science item 49044. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis. The plot of the combined race differential item function evidence for Science item 50121. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis. The plot of the combined race differential item function evidence for Science item 55919. The figure contains points shaded by group. The figure also contains a logistic regression curve for each group. The total linkage levels mastered in is on the x-axis, and the probability of a correct response is on the y-axis.