Name: Jody Kittell

Article: TPS

How to Generate Understanding of the Scientific Process in Introductory Biology: A Student-Designed Laboratory 

Collins, L., & Bell, R., (2004). , American Biology Teacher, 66, 51-53.

SUMMARY:

This article described the reasons why a lab for an introductory college level biology course was student-designed. The reasons for this exercise were 1) increase understanding of the subject matter, 2) involve students in the process of scientific investigation, 3) straightforward, 4) reduce cost, and 5) keep preparation time to a minimum. Prior to re-designing this ‘cookbook’ lab on fermentation, students were told exactly what to do and they did it. At the end of the exercise, the students had little understanding of fermentation. In the new exercise students ask questions, formulate hypotheses, and design and perform experiments. They choose a variable to test, e.g., substrate concentration, yeast concentration, alcohol concentration, or temperature. They collect data and draw conclusions. They are required to write a short laboratory report on the experiment upon conclusion. The students are permitted to submit several drafts of the their reports, since they have relatively little experience writing scientific papers. The advantages of this type of exercise are 1) encourage students not to take knowledge for granted but to engage in creating it, 2) requires students to think, 3) involves hypothesizing, experimenting, and revising hypotheses, 4) allows data collection and interpretation, 5) is collaborative, 6) improves writing skills, 7) is straightforward and easy to perform, 8) is inexpensive, and, 9) requires little laboratory preparation.

Students see from the equation that the amount of fermentation can be determined by measuring carbon dioxide production. They are asked to consider what variables might effect fermentation in yeast: type of substrate, yeast concentration, temperature, and ethyl alcohol concentration. Other variables of the students’ choice include: yeast suspension, sugar solutions, artificial sweetener solutions, and water bath use. The students meet as a team of three or four to discuss their experiment. After looking at many possible effects on yeast fermentation, they choose the variables they want to test. They formulate a hypothesis about the effect their variable will have on yeast fermentation. They decide how they will test their hypothesis. It is expected that they will understand the importance of controls in their experiment. After having their experimental design approved by the instructor, a list of required materials are provided so only those that are needed will be prepared and supplied for the next meeting.

It was found that the students enjoy the challenge of designing and performing their experiment. This type of exercise encourages the students’ active engagement in developing their problem solving skills that will be valuable to them in the world after college.

REACTION:

This was a very simple article to read and understand. It really made me recollect on my experiences of laboratory exercises and what I learned or did not learn from them. I vaguely remember conducting a fermentation lab. I do remember that all my labs were straight from the lab manual and all we did was follow the instructions. It did not really matter if we understood why we were doing it, as long as we got the expected results. Many times I did not get the expected results, therefore, I became quite good at making up reasons why my experiment failed.

I think that having the students design their own experiment is a really good idea. Not only do they have a complete understanding of how to test for certain variables, but they also have the understanding of why they are testing their chosen variables. They get to prove or disprove their hypotheses. This way, they don’t have to make ‘excuses’ why their experiment did not proceed to the expected outcome as stated in the lab manual. It is easier to explain why your own hypotheses were disproved than why your experiment failed according to some ‘cookbook’ lab experiment. This seems to be a relatively simple lab exercise, but the knowledge gained through one’s own experimental design processing and the knowledge and process skills acquired is immeasurable.