Raker Research Group

🚨 New Research from the Raker Research Group 🚨

Evaluating electrophile and nucleophile understanding: A large-scale study of learners’ explanations of reaction mechanisms

ABSTRACT: "A deep understanding of organic chemistry requires a learner to understand many concepts and have fluency with multiple skills. This understanding is particularly necessary for constructing and using mechanisms to explain chemical reactions. Electrophilicity and nucleophilicity are two fundamental concepts to learning and understanding reaction mechanisms. Prior research suggests that learners focus heavily on explicit structural features (e.g., formal charge) rather than implicit features (e.g., an open p-orbital) when identifying and describing the role of electrophiles and nucleophiles in reaction mechanisms; however, these findings come from small-scale, interview-based investigations with a limited number of reaction mechanisms. The work reported herein seeks to further explore the meaning learners ascribe to electrophiles and nucleophiles by evaluating 19,936 written explanations from constructed-response items asking what is happening in reaction mechanisms and why it happens for 85 unique reaction mechanisms across a yearlong postsecondary organic chemistry course. To analyze these data, we developed an electrophile rubric to capture learners’ level of explanation sophistication (Absent, Descriptive, Foundational, and Complex); this electrophile rubric is complementary to a nucleophile rubric previously reported in the literature. Our data show proportional levels of explanation sophistication for electrophiles and nucleophiles (τb = 0.402) across these written explanations of reaction mechanisms. We note that learners’ explanations of nucleophiles tend to be at a higher level than their explanations of electrophiles. While this finding does support prior literature reports, we also found that explanations of mechanisms involving reductions of pi-bonds (e.g., carbonyls) tended to be more sophisticated for electrophiles than for nucleophiles. Overall, our results support the claim that learners are able to discuss both electrophilicity and nucleophilicity; however, learners discuss electrophilicity and nucleophilicity at different levels of sophistication where nucleophilicity predominates for most reaction types."

Posted on February 2, 2023

🎓 Congratulations Stephanie Frost! 🎓

Congratulations to Stephanie Front for successfully completing their Candidacy Defense!

Posted on January 31, 2023

🚨 New Research from the Raker Research Group 🚨

Association of malleable factors with adoption of research-based instructional strategies in introductory chemistry, mathematics, and physics

Some takeways:

1. Different malleable factors are associated with instructors across stages of EBIP adoption (awareness, tryout, adoption)
2. Classroom spaces remain important! Large class sizes and active learning classrooms may drive instructors to try new pedagogies
3. Instructors’ perceived value of how teaching is assessed is associated with greater odds of EBIP adoption. Policy changes may drive change
4. Instructors’ dissatisfaction with student learning may lead to new teaching strategies and tryout/adoption of EBIPs
5. Engagement in prof development programs is critical and should be tailored to meet instructors’ needed based on adoption stage
6. Instructors’ growth mindset is associated with EBIP adoption. Their persistence in the innovation process may lead to sustained adoption
7. Increase stage of EBIP adoption (awareness, tryout, adoption) is associated with a decrease in percent time lecturing

There is no one-size-fits-all solution to instructional change; malleable factors can inform different change strategies based on the desired outcome.

Posted on November 21, 2022

🎓 Congratulations Dr. Brandon J. Yik! 🎓

Congratulations to Dr. Brandon J. Yik for successfully defending their dissertation today! Dr. Yik is the fourth student to graduate a Ph.D. from the Raker Research Group.

Posted on October 4, 2022

🎓 Congratulations Dr. Aaron Clark! 🎓

Congratulations to Dr. Aaron M. Clark for successfully completing their doctoral degree requirements! Dr. Clark is the third student to graduate with a Ph.D. from the Raker Research Group.

Posted on July 22, 2021

Welcome Dr. Connor!

A warm welcome to Dr. Megan Connor who has joined the Raker Research Group as a postdoctoral researcher! Dr. Connor will be working on several of our NSF funded research initiatives!!!

Posted on June 1, 2021