Revisiting and refining relations between nonsymbolic ratio processing and symbolic math achievement

In their 2016 Psych Science article, Matthews, Lewis and Hubbard (2016, https://doi.org/10.1177/0956797615617799) leveled a challenge against the prevailing theory that fractions—as opposed to whole numbers—are incompatible with humans’ primitive nonsymbolic number sense. Their ratio processing system (RPS) account holds that humans possess a primitive system that confers the ability to process nonysmbolic ratio magnitudes. Perhaps the most striking finding from Matthews et al. was that ratio processing ability predicted symbolic fractions knowledge and algebraic competence. The purpose of the current study was to replicate Matthews et al.’s novel results and to extend the study by including a control measure of fluid intelligence and an additional nonsymbolic magnitude format as predictors of multiple symbolic math outcomes. Ninety-nine college students completed three comparison tasks deciding which of two nonsymbolic ratios was numerically larger along with three simple magnitude comparison tasks in corresponding formats that served as controls. The formats included were lines, circles, and dots. We found that RPS acuity predicted fractions knowledge for three university math placement exam subtests when controlling for simple magnitude acuities and inhibitory control. However, this predictive power of the RPS measure appeared to stem primarily from acuity of the line-ratio format, and that predictive power was attenuated with the inclusion of fluid intelligence. These findings may help refine theories positing the RPS as a domain-specific foundation for building fractional knowledge and related higher mathematics.

Using Rasch analysis for determining the cut score of a computer science placement exam

A key strategy for broadening computer science participation in the Chicago Public Schools has been the enactment of a yearlong computer science course as a high school graduation requirement. The Exploring Computer Science (ECS) curriculum and professional development program serves as a core foundation for supporting policy enactment. However, students with prior background in computer science might find the course repetitive. This paper reports on district efforts to develop a placement exam for students to take an advanced computer science course in lieu of the introductory computer science course. The placement exam tasks were modeled after the ECS exam tasks but with higher difficulty. We used Rasch modeling to equate the placement exam tasks to the ECS exams and to establish a cut score for passing the placement exam.

Student Preparedness and Success in Introductory Psychology

Background: Reading comprehension and writing ability are critical to students’ success in introductory psychology. However, these generally are not prerequisites. There is conflicting evidence with regard to the effectiveness of remedial reading and writing classes for students with low placement exam scores. Objectives: To explore whether ACCUPLACER® test scores help predict performance in introductory psychology, and the effectiveness of reading and writing remediation classes in helping students, particularly those with low ACCUPLACER® scores. Method: Logistic regression analyses were used, to explore whether ACCUPLACER® test scores helped predict performance, and whether completing remediation classes helped students pass, controlling for ACCUPLACER® and WritePlacer® scores, at an upstate New York community college, between the years 2010 and 2015. Results: Placement test scores did help to predict successful course completion. There was not a statistically significant difference in successful course completion between students who passed the remedial courses and those who did not take them. Conclusions: Success in introductory psychology requires college-level reading and writing. Remedial courses’ value in students’ success in this class appears relatively small or non-significant. Teaching Implications: We propose solutions that may be more effective, involving embedding the remediation in the course, or in closely linked ancillary sections.