Research on the test structure of the Force Concept Inventory (FCI) has largely ignored gender, and research on FCI gender effects (often reported as "gender gaps") has seldom interrogated the structure of the test. These rarely crossed streams of research leave open the possibility that the FCI may not be structurally valid across genders, particularly since many reported results come from calculus-based courses where 75% or more of the students are men. We examine the FCI considering both psychometrics and gender disaggregation (while acknowledging this as a binary simplification), and find several problematic questions whose removal decreases the apparent gender gap. We analyze three samples (total N pre ¼ 5391, N post ¼ 5769) looking for gender asymmetries using classical test theory, item response theory, and differential item functioning. The combination of these methods highlights six items that appear substantially unfair to women and two items biased in favor of women. No single physical concept or prior experience unifies these questions, but they are broadly consistent with problematic items identified in previous research. Removing all significantly gender-unfair items halves the gender gap in the main sample in this study. We recommend that instructors using the FCI report the reduced-instrument score as well as the 30-item score, and that credit or other benefits to students not be assigned using the biased items.

No abstract

Research on the test structure of the Force Concept Inventory (FCI) has largely been performed with exploratory methods such as factor analysis and cluster analysis. Multidimensional Item Response Theory (MIRT) provides an alternative to traditional exploratory factor analysis which allows statistical testing to identify the optimal number of factors. Application of MIRT to a sample of N ¼ 4716 FCI post-tests identified a 9-factor solution as optimal. Additional analysis showed that a substantial part of the identified factor structure resulted from the practice of using problem blocks and from pairs of similar questions. Applying MIRT to a reduced set of FCI items removing blocked items and repeated items produced a 6-factor solution; however, the factors still had little relation the general structure of Newtonian mechanics. A theoretical model of the FCI was constructed from expert solutions and fit to the FCI by constraining the MIRT parameter matrix to the theoretical model. Variations on the theoretical model were then explored to identify an optimal model. The optimal model supported the differentiation of Newton's 1st and 2nd law; of one-dimensional and three-dimensional kinematics; and of the principle of the addition of forces from Newton's 2nd law. The model suggested by the authors of the FCI was also fit; the optimal MIRT model was statistically superior.

The "gender gap" on various physics conceptual evaluations has been extensively studied. Men's average pretest scores on the Force Concept Inventory and Force and Motion Conceptual Evaluation are 13% higher than women's, and post-test scores are on average 12% higher than women's. This study analyzed the gender differences within the Conceptual Survey of Electricity and Magnetism (CSEM) in which the gender gap has been less well studied and is less consistent. In the current study, data collected from 1407 students (77% men, 23% women) in a calculus-based physics course over ten semesters showed that male students outperformed female students on the CSEM pretest (5%) and post-test (6%). Separate analyses were conducted for qualitative and quantitative problems on lab quizzes and course exams and showed that male students outperformed female students by 3% on qualitative quiz and exam problems. Male and female students performed equally on the quantitative course exam problems. The gender gaps within CSEM post-test scores, qualitative lab quiz scores, and qualitative exam scores were insignificant for students with a CSEM pretest score of 25% or less but grew as pretest scores increased. Structural equation modeling demonstrated that a latent variable, called Conceptual Physics Performance/Non-Quantitative (CPP/NonQnt), orthogonal to quantitative test performance was useful in explaining the differences observed in qualitative performance; this variable was most strongly related to CSEM post-test scores. The CPP/NonQnt of male students was 0.44 standard deviations higher than female students. The CSEM pretest measured CPP/NonQnt much less accurately for women (R 2 ¼ 4%) than for men (R 2 ¼ 17%). The failure to detect a gender gap for students scoring 25% or less on the pretest suggests that the CSEM instrument itself is not gender biased. The failure to find a performance difference in quantitative test performance while detecting a gap in qualitative performance suggests the qualitative differences do not result from psychological factors such as science anxiety or stereotype threat.

Failure rates observed (13 +/- 6 percent for school failures, 17 +/- 5 percent for scores below 95 on a collective IQ test) were far below those expected from the social class of birth (55 percent, 51 percent) or observed in a control group (56 +/- 8 percent, 49 +/- 9 percent) but close to those expected from the social class of adoption (15 percent, 15 percent).

Medium- and long-term effects of types of placement of the offspring of lower class families have been studied. The progeny of 28 mothers was reconstituted. The subjects were divided into three groups: 35 children abandoned and adopted early in privileged environments (A), 46 'biological mother-reared' children remaining in their disadvantaged social environments (B) and 21 children raised in institutions or foster homes (C). Analyses focused on IQ, scholastic performance and behaviour. Results show that the social environment has important effects: the differences between the three groups are very significant. For A and B groups tested in the schools, comparisons were made with the classmates. For the C group the effects of long-term emotional deprivation are superimposed on the effects of the social environment.

No abstract

Module Analysis for Multiple-Choice Responses (MAMCR) was applied to a large sample of Force Concept Inventory (FCI) pretest and post-test responses (Npre = 4509 and Npost = 4716) to replicate the results of the original MAMCR study and to understand the origins of the gender differences reported in a previous study of this data set. When the results of MAMCR could not be replicated, a modification of the method was introduced, Modified Module Analysis (MMA). MMA was productive in understanding the structure of the incorrect answers in the FCI, identifying 9 groups of incorrect answers on the pretest and 11 groups on the post-test. These groups, in most cases, could be mapped on to common misconceptions used by the authors of the FCI to create distactors for the instrument. Of these incorrect answer groups, 6 of the pretest groups and 8 of the post-test groups were the same for men and women. Two of the male-only pretest groups disappeared with instruction while the third male-only pretest group was identified for both men and women post-instruction. Three of the groups identified for both men and women on the posttest were not present for either on the pretest. The rest of the identified incorrect answer groups did not represent misconceptions, but were rather related to the the blocked structure of some FCI items where multiple items are related to a common stem. The groups identified had little relation to the gender unfair items previously identified for this data set, and therefore, differences in the structure of student misconceptions between men and women cannot explain the gender differences reported for the FCI. *