Performance-Based Assessment: Chemistry
Performance-based assessment is a way for students to demonstrate knowledge, skills, and material that they've learned. Performance-based assessment measures how well students can apply or use what they know, often in real-world situations. Research has shown how this assessment practice helps teachers and principals support students in developing a deeper understanding of content, and provides a means to assess higher-order thinking skills.
How It's Done
Performance-based assessment starts with the curriculum, instruction, or unit that you're already teaching. How do you design a performance-based assessment for this content? Since PBA requires students to demonstrate knowledge, skills, and concepts, they are usually asked to create a product or response, or to perform a specific task or set of tasks.
At Hampton High School, teachers calibrate their assessments against a rigor scale so that the level of performance is also high. They use the common Rigor, Relevance, and Relationships framework, which shows that higher levels of rigor and relevance embody higher levels of cognition and application. When designing assessments, teachers ask, "What is the level of performance? Do we want short-term memory and fragmented applications from kids, or do we want comprehensive understanding of big ideas?" This changes the whole picture from content measures to student performance measures.
For example, a performance task in writing would require students to produce a piece of writing rather than answering multiple-choice questions about grammar or the structure of a paragraph. Performance assessment is authentic when it mimics the work done in real-world contexts. In another example, an authentic environmental science performance task might require a student to research the impact of fertilizer on local groundwater and then report the results through a public service campaign (like a video, radio announcement, or presentation to a group).
Performance assessment taps into students' higher-order thinking skills, such as evaluating the reliability of information sources, synthesizing information to draw conclusions, or using deductive/inductive reasoning to solve a problem. Performance tasks may require students to make an argument with supporting evidence, conduct a controlled experiment, solve a complex problem, or build a model. These tasks often have more than one acceptable solution or answer, and teachers use rubrics as a key part of assessing student work.
Chemistry Research Project
Hampton High School's PBA Chemistry Research Project was designed as a key part of students' fourth marking period. Its three parts are a model, a video, and an in-class debate. The purpose is to demonstrate students' understanding of the chemistry and compounds they've studied during the quarter.
In the Resources tab, you'll find all the materials used for the project. Created by Hampton teachers, these materials include:
- Project directions
- Compound selection list
- Model instructions
- Rubrics to assess the project
The project time frame is about 4-5 weeks.
Students receive a list of research categories and may choose any compound they want to work on. For example, they can choose polymers (i.e. nylon, Kevlar, Teflon, types of glue, various plastics); vitamins and antioxidants (i.e. vitamins A, B6, B12, C, etc.); sweeteners (i.e. sugar, saccharin, aspartame, sucralose, etc.); or fuels (i.e. octane, propane, diesel, kerosene, etc.). Students are responsible for learning about a particular compound, and presenting the following:
1. The Model
In order to demonstrate understanding of their compound's basic chemistry, students make a model of the compound. Along with proper bond angles, bonding principles, bond lengths, students need to show relevancy by constructing the model out of products that utilize the compound. For example, a student working on caffeine created a model from Coke cans. Novocain was made from tiny bottles of mouthwash and dental sticks. One student built a model of nitroglycerin from tiny hearts, because nitroglycerin is used to treat heart attacks; but another student working on the same compound made her model out of dynamite sticks, since nitroglycerin is also used as an explosive.
2. The Video
In the project's video component, students present the pros of their compound, including how it works, how we use it, its history, future applications, and examples of the compound at work.
Students learn the basics of video production and have access to the technology needed to create these videos. Less technology-based options might include a slideshow or PowerPoint, a poster board, or any other product that would show the same demonstration of learning.
3. The Debate
Students are paired in the debate so that one compound is compared to another within the same category. For example, in the fuels category, one student represents diesel, the other octane. In the sweetener category, one student picks sugar and another represents saccharine. For each compound, arguments center around which compound is more "effective" in its category (sweetener, polymer, etc.). Students structure their debate around this key question.
Students come to their debate with some knowledge about their opponents' compound to help strengthen their rebuttal. The debates begin with student-created videos. As each video plays, students are responsible for creating an opposing argument to counter their opponent's research, and making an argument for why their opponent's compound is not as effective. During the rebuttal, they use statistics, dates, sources, and anything to show the relevant research. In their closing arguments, students sum up the pros of their own compound, and conclude with why theirs is more effective than their opponent's.
The debate is followed by a peer vote. Everyone in the class casts a vote as to whose argument was most convincing, and what compound is most effective.
Assessment: Utilizing Rubrics
Teachers design a rubric for each part of the project, showing how students will be graded for their work, and give it to students ahead of time. Every teacher weighs each part of the project and develops a point system to reflect the amount of work and time students are expected to put into each part of the project. The entire project is worth 175 points, including:
- 60 for the video
- 60 for the model
- 40 for the debate
- 10 for a bibliography/works cited (where students found their information)
- 5 for the peer vote
Each component of the project has its own separate rubric and a range of 0-15 points (absent, poor, fair, good) on a number of categories. For example, the video rubric grades the organization and clarity of the video, its use of examples and facts, strength of the argument, presentation, and video quality. The debate rubric assesses the use of video material, strength of the opposing argument, and effectiveness of the rebuttal. Students understand ahead of time what they'll be assessed on.
For each rubric, the teacher also provides clear comments on each component of the project, to validate why the particular grade is being awarded. During the debate, for example, the teacher takes notes on how well students present their pros and cons, and whether they cite statistics and research in support of their compound. Notes are crucial when grading with a rubric, as there is always gray area where a student may say, "I think I deserve a better grade here for this reason." As a teacher, it's important to have justification, evidence, and reasons why a student may or may not have scored higher in a particular area. "Look, here's a point where why I am sliding it higher on the scale, or here's why I didn't slide it higher, because I didn't see this." All students receive a copy of the rubric and notes with their final grade at the end of the project.