Kristen Murphy
Chemical Education
Assistant Professor
PhD, UW-Milwaukee
(414)229-4468
e-mail: kmurphy@uwm.edu
Selected Publications
- Enhancing students' perception of scale and atomic unitizing
- Development of a new assessment strategy (rapid knowledge assessment) for understanding students' problem solving strategies
Enhancing students' perception of scale and atomic unitizing
Grasping scale outside the visual realm can be difficult particularly with regards to the very small. Undergraduate students in preparatory and introductory chemistry courses, for example, are required to begin thinking about certain concepts in chemistry on a particle level, which is orders of magnitude smaller than the resolving ability of the human eye. The development of a student's scale conception outside of the concepts of chemistry has been noted as an important component of a student's overall science literacy by the AAAS (American Association for the Advancement of Science). Research has shown that students need to continue cultivating their understanding of scale, particularly down to the nanometer size, beyond their elementary and secondary education years. Additionally, it has been found that students who utilize instrumentation in these very small regions have a better concept of scale than those who do not.
This project measures changes in understanding in both a student's scale perception and unitizing on the atomic level. Unitizing is the development and use of a convenient or familiar unit. For instance, although we use a common length of the meter this is on the order of human size (we unitize to what we are most familiar) and it is often only through necessity that we unitize to other units (for example, a light year). It is expected that students in preparatory or introductory college chemistry "think conceptually" of atoms and molecules interacting. The precursor expectation to this is unitizing on the atomic level (with the unit of the atom). Once students unitize on the atomic level, the transfer of both enhanced scale perception and atomic unitizing to other specific content areas are measured.
This project utilizes the previous studies by presenting students in preparatory and introductory chemistry courses with images generated by a real-time, remote access scanning electron microscope or portable, in-class scanning tunneling microscope for inquiry-based exercises in during lecture. Both informal and formal assessment measure the efficacy of the instrumentation utilized during the lecture demonstrations in enhancing students' scale perception, atomic unitizing and transfer to other specific content areas.
Rapid knowledge assessmentImproving students' learning and understanding in science, technology, mathematics or engineering (STEM) disciplines coincides with improving methods of assessing learning and understanding in STEM. Cognitive load theory, a theory from cognitive psychology, has been applied in mathematics where expertise of a student was assigned based on a rapid-measurement scheme assessing which immediate first step was taken in the problem-solving process. This measurement coupled with a measure of the student's reported mental workload provided greater insight into the problem-solving strategies employed by the student than performance alone. Additionally, once expertise can be approximated, instructional strategies can be tailored to further enhance performance on subsequent assessments where research has shown the lower expertise students performed better after instruction with worked examples while higher expertise students performed better with problem solving instructions.
This project will develop a rapid knowledge assessment (RKA) for preparatory and introductory college chemistry modeled after the rapid-measurement scheme utilized in mathematics. Efficiency in students' problem solving strategies ia assessed through the reported immediate first step, correct or incorrect response to the exercise overall and student reported mental effort. Coding and analysis of the responses includes examining groupings as well as problem solving efficiency. For instance, if students utilize similar problem-solving strategies for similar problems, groupings of similarly coded student responses can be identified. In addition to reported groupings within specific content areas, groupings between specific content areas can also be identified. Validation of this instrument will also include expert analysis of student responses, student problem solving strategies as reported through think-aloud protocols, and longitudinal analysis of similar items in preparatory to introductory college chemistry.
