Mary O'Donnell Emenike


joined Bretz Group in August 2006

B.S. Nazareth College, 2006
Ph.D. Miami University, 2010

Dissertation: What is a Chemical? Fourth-Grade Children's Categorization of Everyday Objects and Substances

     For students learning science, a potential source of difficulty arises from the fact that many words used in formal science instruction are used informally in everyday communication. Chemical is one such word with multiple uses and meanings. The word chemical has different meanings when used in everyday language than in scientific language. Although children do not take a formal chemistry class in elementary school, they are expected to learn about chemical principles (chemical properties, physical properties, chemical change, and physical change) in fourth or fifth grade. Because of the everyday use of the word chemical, children are likely to have constructed some meanings about the word chemical prior to formal instruction. This prior knowledge is an important and necessary piece in the learning process. The learning theories of children's science and meaningful learning framed this qualitative investigation of fourth grade children's conceptual knowledge of chemicals. During semi-structured interviews, children's ideas about chemicals were elicited as they categorized everyday objects and substances that were related to chemicals. The children described prototypical chemicals such as cleaning substances, acids, gasoline, lead, and mercury. The properties of chemicals described by the children suggest that the children think about chemicals within an anthropocentric framework. Children related the purposes and attributes of chemicals to human interaction with the chemicals. The implications for teaching chemical principles to children are discussed. A manuscript was published in School Science and Mathematics.


Cognate Research Project #1: Investigating the Retention Mechanisms of Liquid Chromatography using Solid-Phase Extraction Cartridges

      Liquid chromatography (LC) experiments for the undergraduate analytical laboratory course often illustrate the application of reversed-phase LC to solve a separation problem, but rarely compare LC retention mechanisms. In addition, a high-performance liquid chromatography instrument may be beyond what some small colleges can purchase. Solid-phase extraction (SPE) cartridges offer an inexpensive alternative, while still providing effective model columns for investigating LC retention mechanisms. We have shown that the four major retention mechanisms (normal-phase, reversed-phase, ion-exchange, and size-exclusion) can be investigated experimentally using two types of SPE cartridges (silica and C18) as columns. The C18 cartridges can be pre-treated with anionic or cationic polymers to produce ion-exchange columns. The concept of post-column detection is also introduced. This experiment is suitable for a first-year general chemistry course or a third-year analytical course to illustrate the importance of solvent polarity and the types of retention mechanisms employed in separation science. A manuscript was published in the Journal of Chemical Education.


Cognate Research Project #2: Meaningful Learning in a First-Year Chemistry Laboratory Course: Differences across Classical, Discovery, and Instrumental Experiments

      At Miami University in Oxford, Ohio, the second-semester general chemistry course for chemistry majors is the equivalent of an analytical laboratory course. The experiments in the course are classified as classical, discovery, or instrumental on the basis of their structure and purpose. To investigate students’ perceptions of learning through these three categories of experiments, six students were interviewed three times over the course of the semester, both individually and in pairs. The students’ descriptions of their learning in the laboratory were analyzed through the lens of Novak’s theory of meaningful learning and were compared with the instructor’s learning goals for the experiments. Students’ prior knowledge and the structure of the experiments influenced whether the students described their learning in the cognitive, psychomotor, and/or affective learning domains. A manuscript was published in the Journal of College Science Teaching.

© 2017   Stacey Lowery Bretz   Miami University   Department of Chemistry & Biochemistry   Oxford, OH 45056   513.529.3731