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EES 225: Earth Materials

Samantha Tramontano, Earth & Environmental Science, working with Guilherme Gualda, Associate Professor and
Lily Claiborne, Sr. Lecturer of Earth & Environmental Science


Visual and spatial reasoning and understanding are important skills for many disciplines within the Earth Sciences, and developing those skills is one of the major challenges students face when they are first learning how to use microscopy as a tool for understanding optical mineralogy. Students struggle with building basic microscopy skills that are essential for their progression as Earth scientists.

In this project, we incorporated a visual aid component for the optical mineralogy portion of the Earth Materials class here at Vanderbilt. Specifically, we developed videos to show students what they should be looking for when examining minerals and to highlight the observation protocols and spatial skills they will need to use while doing so. The videos were accompanied by low-stakes quizzes that allowed students to assess their own understanding. We hypothesized that these videos enabled students to be more self-sufficient in lab and enhanced their confidence and engagement.

My project asked: Will exposing undergraduate geology students to optical microscopy figures in videos prior to lab assist in the acquisitions of skills required to describe and distinguish Earth materials?

Our overall goal was for the students to be able to implement new microscope skills in describing and distinguishing minerals in thin section. More specifically, our learning objectives were for students to be able to:

  • Identify the parts of the petrographic microscope and how to manipulate it for different tasks
  • Determine optical properties of any mineral
  • Characterize a mineral in plane-polarized light and cross-polarized light
  • Self-assess and explain confidence in their characterization and naming of minerals

Four units were hosted on a WordPress website: and included accompanying exercises hosted on Google Forms.

The units and topics covered include:

  • Plane Polarized Light: color, pleochroism, relief, transparent vs. opaque
  • Cross Polarized Light: Interference colors, extinction angles, birefringence, isotropy vs. anisotropy, fast & slow ray
  • Uniaxial Minerals: Interference figures, optic sign, flash figure, characterizing along epsilon and omega
  • Biaxial Minerals: Interference figures, optic sign, 2V angle, flash figure, characterizing along alpha, gamma, & beta


Pre-Lab Videos & Questions

For the purpose of this study, the videos and questions were emailed prior to a weekly lab with the intent of familiarizing the student with the types of images and information he/she should obtain with the microscope. The learning objectives of these videos support the merging of theoretical goals and practical goals. Using these videos with a lab where theory is taught will optimize the success of the student. Two example videos are shown below.


We assigned one video per week for the first half of the fall semester. Short formative assessments accompanied the videos in a Google Forms-hosted assignment (example, below). This assignment will be given credit based on completion and is intended to aid in student self-awareness, or metacognition.

Summative assessments include weekly homeworks and a lab final. The combination of the pre and post lab assignments is expected to help students understand how much extra time is needed to hone and fully understand the basic optical microscopy skill-set.




Assessing the Effectiveness of the Online Quizzes and Videos

The effectiveness of the videos were assessed by comparing the homework and lab final grades of the students this year with those of the students last year. The homework assignments and lab final were part of the original course framework and remained consistent between the two years. We expected the students to perform better and with more confidence. The students were also asked to fill out the questionnaire below. The answers after each week were compiled and compared for the fall 2015 Earth Materials course in the Earth and Environmental Sciences department (EES 225).



How did they feel about it? Vanderbilt students were surveyed each week to determine response to pre-lab assignments. Larger square symbols indicate the mean response; small circles indicate individual student responses; each week is shown in a different color. The students generally found that the pre-lab assignments were helpful for lab exercises, and they reported higher self-confidence inside and outside of lab.


How did they watch it? Data from YouTube was analyzed for students using the exercises at Vanderbilt University and at Illinois State University. While Vanderbilt students visited the videos most frequently, Illinois State students watched a larger percentage of each video.

No significant difference in homework and lab final grades between 2014 and 2015 Vanderbilt students.

You can see more results and learn more about the project by viewing the project poster.


Tramontano, S; Gualda, GAR; Claiborne, L; Brame, C. 2015, Developing and incorporating instructional videos and quizzes as a blended and online learning component in an undergraduate optical microscopy curriculum., Abstract ED53A-0848 presented at 2015 Fall Meeting, AGU, San Francisco, Calif., 14-18 Dec.