There could be many experiments used, but the one chosen on the solubility of gases in water is important because of the requirements of a High School Chemistry syllabus. In terms of developing last year’s unit along the lines of Dewey’s pedagogy, the most serious omission was evaluation. It is proposed here that the final lesson be primarily used as means to measure skills and learning achieved in the unit.
It was Dewey’s contention that using extrinsic rewards in education demoralized true educational performance. In current reforms, it is proposed that the method of evaluation correspond to that used by professional scientists, research laboratories and job performance. Dewey held that the school was an intimate and inseparable part of the wider community and what happened in a school should parallel what occurs in other institutions, hence democracy belonged to school as logically as it did elsewhere. What exactly does that mean for this unit?
One important criterion of ability is presenting research for publication. As is normal in contemporary science, this would be a group project. The four main parts of the evaluation would be the definition of the problem and hypothesis to be tested, the description of the experiment as a repeatable process, the presentation of results so that they are clearly understandable and the self-criticism in the validity of the results, implications and so forth. There are differing techniques of giving individual grades—the one I like is to assign specific responsibilities to individuals (roles chosen by the group) and hold them responsible for that aspect of the project. Projects could be published on an Internet page for the High School.
The preferred mode of giving an overall grade is for students to compile a portfolio and choose the best work to present for grading. My preference is for students to keep a log book of all work carried out, rather like a personal diary and to use it along with work carried out in the unit to write a monograph on the subject of the unit. Again, these can be published on a Web page in the Internet.
In terms of keeping jobs, attendence and cooperative slcills are irnportant factors in assessment. Looking after equipment, initiative and individual responsibility towards the enterprise are criteria in general assessment used in professional labsratones. Learning accountability in this way, I think, begins in school and so should enter into the overall assessment.
Assessment is rarely carried out in the business or the scientific community by one person. The ‘viva’ is an example of an interview with teacher and external examiner (usually another teacher, but in this case it could be a volunteer parent or local business man etc.) who could participate in assigning grades. Students could be present to answer questions. It is particularly good for assessing the work of borderline or outstanding students, but for all students it quickly reveals how much is known and understood about the subject matter. Alternatively the viva or oral could be carried out by the class as a whole, rather as in peer trials, and guided by the teacher in the background.