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CHEM 3135W: Forensic Analytical Chemistry


Ryan Bowen, Chemistry, working with
Susan Verbene-Sutton,
Senior Lecturer in Chemistry

Overview

Proficient laboratory investigation is a highly useful skill that many employers seek when hiring in research positions. The techniques learned in a laboratory translate into strong critical thinking skills as well as adeptness in complex problem-solving within research. Typically, these laboratory skills are not acquired until a budding scientist enters graduate school since many undergraduate labs are more procedural than investigative. Ultimately, this system generates a disconnect in science education where students do not build research and laboratory competence until it is expected. Therefore, we have created a module designed to aid students in developing competence toward answering research questions.

Specifically, we have developed online learning materials that help students take an inquiry-based approach to a lab involving high performance liquid chromatography, a technique taught in CHEM 3135W: Forensic Analytical Chemistry at Vanderbilt University. The module utilizes questions that guide the students in asking relevant questions over the material and techniques and includes all background information and protocols necessary for the experiment. Students will use the online learning materials to prepare for the lab session.

If the online materials improve students’ skills in and attitudes about lab investigation, they would be valuable to other chemistry instructors. We therefore plan to gather two types of data to determine the effect of the module on students’ skills and attitudes. First, we plan to conduct observations in the targeted lab session, comparing it to observations in a standard “cookbook” laboratory session as control. Second, we will conduct semi-structured interviews with each consenting student in which the students will be asked to reflect on their experience with the module as well as their comprehension of the concepts and techniques related to the module, and to provide feedback on the structure and usefulness of the module.

Module Materials

The module was developed as a holistic approach to using high performance liquid chromatography. It includes a series of PowerPoint presentations that guide students from standard and sample preparation to shutting down the liquid chromatography instrumentation. There are ungraded questions throughout the PowerPoint presentations that act as formative feedback and check the student’s comprehension of the material. Previous research has demonstrated that segmenting information enhances student engagement and learning (Zhang et. al 2005; Zhang et. al. 2006; Ibrahim et. al. 2012; Guo et. al 2014), therefore the PowerPoint presentations were divided into six sections. One of the sections from the PowerPoint presentation is below.

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The module aims to teach students the instrumentation being used. Detailed schematics of High Performance Liquid Chromatography, like the one below, will be shown to the students to aid in their understanding of the instrument.

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As previously mentioned, ungraded questions can be found throughout the PowerPoint. An example of these questions is shown below.

bowen3As the students progressed through the module they used a “Roadmap” worksheet to take notes. This “Roadmap” encouraged the students to frame their approach so they have structure prior to attempting the experiment. Furthermore, it allowed the students to focus on answering relevant questions pertaining to the concepts being studied.

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After the experiment was completed, consenting students will engage in private one-on-one interviews. Aside from providing general feedback on the module, students will be asked to report on their self-awareness regarding the comprehension of the material, or metacognition. In the article “Design and Validation of an Instrument to Assess Metacognitive Skillfulness in Chemistry Problem Solving” by Cooper and Sandi-Urena, the authors describe metacognition as being broken down into two parts: knowledge of cognition (metacognitive knowledge) and regulation of cognition (metacognitive skillfulness). The figure below was borrowed from the article mentioned.

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Cooper and Sandi-Urena 2009

Metacognitive knowledge includes “declarative knowledge (knowing about things), procedural knowledge (knowing how to do things), and conditional knowledge (knowing why and when to do things).” On the other hand, metacognitive skillfulness includes traditional problem-solving processes such as planning, monitoring, and evaluating. Using this framework to inform our thinking, we designed interview questions to probe the students’ metacognitive knowledge and skillfulness. Some of the questions used in the interviews are included below:

 

  • Can you briefly explain what HPLC is and how it works? (declarative knowledge)
  • When should HPLC be employed in the laboratory? (conditional knowledge)
  • If the pressure on your HPLC instrument is too low or high, what would be some potential causes? (evaluating)
  • What are the steps required when setting up an HPLC experiment? (procedural knowledge/planning)
  • Briefly describe your thought process as you progressed through the module. (monitoring)

 

Results