The practical exam (uploaded) is used as a metric to determine how well students are capable of answering a science question they haven't seen before on their own. In other words, the practical exam tests them on their understanding of the material, and the scientific method itself. If you'd like to measure this against students who have performed the experiment, but did not participate in a discussion session following the experiment, the practical exam scores should give you a measure for how students compare. The questions asked on the practical exam are designed to be as objective as possible to eliminate variation in grading between sections.
This learning object is aimed at getting students to think critically about the data they collect in lab as they collect the data similar to how chemists typically conduct research. They will be given a pre-lab video and a procedure prior to lab, conduct the experiment, and then upload their data to an Excel spreadsheet. Students will then stay in their group to discuss the questions given to them on the worksheet in class with the instructor, and are allowed to continue working on them as a group up until the due date.
Class data from the original experiment will be uploaded to a public Excel spreadsheet that students will have access to in lab and at home, where the averages and standard deviation will be automatically calculated for them. Students will be responsible for all other statistical analysis. TVs, computers, or projectors are required in the lab in order to project data to the students. Directly after the experiment, students will enter a discussion section with a worksheet to work on as a group that relates the collected data back to the original lecture on the topic covered in the experiment.
The purpose of this Learning Object is to teach students not only a difficult concept such as "what is electrochemical potential", but also to teach students how to think about a science question, write a hypothesis, write a procedure to answer said hypothesis, analyze the data, discuss the results as a group, and make a conclusion about their original hypothesis. Although this learning object is written for a general chemistry electrochemistry experiment, it can be easily modified to fit any laboratory experiment in any level of college chemistry (including organic chemistry, biochemistry, etc. The end of the semester for a course that incorporates this template involves a practical exam. In this exam, students are given a science question related to one of the experiments they conducted during the semester such that they use the same techniques used in the original experiment, but answers a far different question. With their laboratory notebooks and previous procedure available to them during the exam, the instructor will be required to not assist the students (outside of safety and waste disposal concerns) in any way regarding the exam.
- TV, computer or projector to project data for students to look at class data.
- Proper aqueous solutions and electrodes needed for the experiment outlined in the experimental procedure.
- If desired, a potentiostat. However, students should be able to design simple galvanic cells to answer the questions.
- Solutions should be prepared before the laboratory experiment and practical exams are administered. However, it is up to your discretion whether you want your students to also make the solutions themselves.
- Lab should take ~2-2.5 hours
- Discussion should be ~1 hr
- DIfferent practical exams for different days in which the lab is being taught, in order to prevent students from sharing what the lab is about
- Students should know what experiment the practical exam will be based on, but should not know the exact question being asked until the day of the exam.
- Worksheets should be due 1 week after the lab, even though students discuss the questions that day. This gives them time to complete the assignment.
- Questions on discussion worksheet should be difficult, given that they have the instructor and students within their group to talk to for help.
- For the practical exam, the solutions should be prepared beforehand to focus their efforts on answering the questions rather than making solutions and preparing to answer the questions. However, it is up your discretion.