The purpose of this study was to investigate the difference between the “atoms first” and the “traditional” curricula. Specifically focusing on which curriculum better aligns to curricular expectations, leads to higher student success when students are grouped together, and when students are differentiated based on several factors. The main difference between the two approaches being the sequence of topics presented in the first semester general chemistry course. This study involves more than 9,500 general chemistry I and II students over 7 semesters with about half of them being taught using the “atoms first” approach. Student success was measured using the American Chemical Society’s (ACS) final examination scores and the final letter grades. Alignment to curricular expectations was determined via a qualitative review of textbooks written for each of the approaches. This showed that the “atoms first” approach better aligns to research supported best practices. An analysis of covariance (ANCOVA) was performed to determine if there is a significant difference between the “atoms first” and the “traditional” curricula. The “traditional” approach was found to lead to higher student achievement for both measures of student success in both chemistry I and II courses. Lastly, multiple linear, multinomial logistic, and binary logistic regressions were run using all of the subgroups – gender, race/ethnicity, major, ACT composite, math ACT, overall GPA, and classroom size – as predictor variables to determine if any significant interactions between the curricular methods and the different subgroups existed. Results found that the relationship between gender, GPA, and classroom size groupings significantly impact student achievement in general chemistry. Specifically, the “traditional” approach lead to higher student success compared to the “atoms first” approach for males, females, below average GPA students, above average GPA students, and students in large classroom settings. However, there are several factors – final examination content, new teacher impact, teacher’s view of science, and withdrawal rate and timing – that need to be taken into account when implementing these findings. Overall, the results of this study provides a cautionary reminder of the many impacts affecting curriculum implementation and the importance of professional development and training during a curriculum transitional period.

This study uses the ACS first-term general chemistry exam to determine if one curriculum approach is more effective in increasing student success than the other based on their performance on the ACS exam. Two chemistry curriculum approaches were evaluated in this study; the traditional curriculum (TC) and the Atoms First (AF) approach. The sample population was first-semester general chemistry students at Collin College in Frisco, TX. An independent sample t-test was used to determine if there were differences in overall performance between the two curriculum approaches on two different versions of the ACS exam. The results from this study show that AF approach may be a better alternative to the TC approach as they performed statistically significantly better on the 2005 exam version. Factor analysis was used to determine if there were differences between the two curriculum approaches by topic on the ACS exam. Eight different topics were chosen based on topics listed on the ACS Examinations Institute Website. The AF students performed better at a statistically significant level than the TC students on the topics of descriptive chemistry and periodicity, molecular structure, and stoichiometry. Item response theory was used to determine the chemistry content misconceptions held by the students taught under both curriculum approaches. It was determined that for both curriculum groups the same misconceptions as determined by the Zcrit values persisted.