The overall CT–PCK Survey functioned similarly across teacher characteristic groups, though some items showed raw differential item functioning above 0.64 logits¶

Claim · All claims
Evidence · 1 study · design r3 · q2
Currency · newest study 2026 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Differential test functioning showed similar overall test difficulty for teachers of similar ability across characteristics, and no item showed statistically significant DIF after multiple-comparison correction; however, several items showed raw difficulty differences greater than 0.64 logits. → Witherspoon 2026

Evidence¶

Witherspoon 2026¶

Witherspoon, E.B.; Dracopoli, M., Hawkins, M., Dahlke, K. (2026). Developing a measure of middle school math teachers' pedagogical content knowledge of computational thinking (REL 2026–007). U.S. Department of Education, Institute of Education Sciences, National Center for Education Evaluation and Regional Assistance. https://ies.ed.gov/use-work/resource-library/report/descriptive-study/developing-measure-middle-school-math-teachers-pedagogical-content-knowledge-computational-thinking

q2 · i? · design · r3

Differential item and test functioning analyses across seven teacher characteristics (tables A12–A15). After correction for multiple comparisons, "no statistically significant differences in the probability of a correct response on any individual item" were found, but raw differences exceeded ETS moderate-to-large DIF thresholds for several items.

"several items did show raw differences in item difficulty by teacher characteristics that were greater than 0.64 logits, which is above Educational Testing Service thresholds indicating moderate to large differential item functioning"

Discussion¶

Related Claims¶

• The 16-item CT–PCK Survey measures CT pedagogical content knowledge for math as a single overall construct — a broader claim this one bears on
• Content experts and practitioner reviews supported the content and face validity of the CT–PCK Survey — related
• Teachers who were White, female, or had five or more years of experience scored about 14 percentage points higher; emergency-certified teachers scored 14 points lower — related
• Some items positioned close together across booklets were also flagged as DIF, possibly due to Type I error from sampling — related
• ICC method flags seven items with the largest DIF indices, two of which show slight nonuniform DIF that the unsigned-area measure understates — related
• Seven items exhibit absolute gender DIF by the LDF method, flagged when the total-score line falls outside .95 confidence bands — related
• The 16-item CT–PCK Survey shows internal consistency reliability around .71–.72 and person separation reliability of .69 — related
• Teachers scored across a wide range on the CT–PCK Survey, averaging about 61 percent correct, with 92 percent scoring above chance — related
• Cultivate survey items function without systematic bias across student groups by race/ethnicity, gender, economic disadvantage, learning differences, or EL status — related
• DIF analysis finds mostly negligible or slight-to-moderate differential item functioning, with only one item showing moderate-to-large DIF favoring Asian over White participants — related
• The Fisher Fellowship selection instrument is reliable, though three of 34 items had relatively low levels of one type of reliability — related