General Chemistry laboratory is possibly the best place to instill both enthusiam for and understanding of chemistry in undergraduates. The hands-on experience combined with strange phenomena they’ve never seen before engages their interest and stirs their curiosity. Unfortunately, the traditional approach to lab instruction - prelab lecture followed by an experiment and a write up - doesn’t use the venue for all it could be worth as a teaching tool. First, it doesn’t necessarily work as a means of developing intuition about the chemical principles encountered in lecture, because the prelab lecture means almost nothing without the students having seen (or done) the actual experiment. This was nicely described by Pasl Jalil in the Journal of Chemical Education in 2006. Second, it most definitely doesn’t seem to be a good way to introducing students to managing experimental data.
The failure of the traditional mode of genchemlab is quite evident in students’ lab reports. They tend to focus extreme attention on the mechanics of the calculations and consider chemical principles only as an afterthought when answering discussion questions. It is often the case that no chemical logic or even common sense is present in their discussions. For example, they have a very difficult time offering quantitative explanations for errors they may have encountered, and frequently their explanations run opposite to what one would expect if attention had been paid to chemical principles.
I suspect that problems such as this have three main sources. First, beginning students have very little skill at making observations and forming hypotheses to explain what they observe. Second, as instructors, we require (and rightly so) that students pay attention to details such as proper recording of data, use of notebooks, correct significant figures and rounding in calculations, all of which tends to focus students in lab on the bits and pieces and not on the larger ideas they are encountering. Finally, the sheer volume of new material that the students are encountering is intimidating and frequently overwhelming; in their efforts to assimilate this material, they seem to have little time or brain power left to dedicate to developing a simple skill – scientific common sense.
My goal in this project is to make the general chemistry lab experience more thought provoking, with an emphasis on understanding the chemistry that is occurring while it is occurring as opposed to having the students try to piece together the puzzle of what happened after the fact. I have two basic hypotheses. First, too much time is often spent on experimentation, which makes it difficult for the instructor to engage with students about the experiment and what it is telling them. Second, post-lab lectures based on fresh experimental results would offer a distinct advantage to pre-lab lectures in terms of increasing the students’ comprehension and retention of the chemical principles encountered in lab.
Ideally, the students would be able to generate a real-time common database of their experimental data. By compiling all of their results into an averaged data set, the students would have access to better quality data on which to base their scientific interpretations. This is an advantage to strong and weak students alike. Some kind of remote data entry system to enter results into the database (a laptop) would be needed. After the database is complete (or perhaps when it is close to complete), the instructor would be able to use the results to illustrate any of several principles: measurements and errors; the relationship between physical measurements and underlying chemical principles; data handling and analysis; assessing experimental error in the lab.
This all requires that the technology allow the instructor to access the data in lab, perform relevant calculations with the data that provide quantitative results as quickly as possible for discussion, and simulate hypothetical situations to see how the results respond to things such as experimental errors or altered experimental conditions. It sounds like Steve Gallik has something of the sort going in his biology labs (where is his site?). I am also curious to know whether something like InterChemNet or possibly UbiquitousPresenter would help meet this need.
I still imagine students using traditional notebooks and submitting the pages with their lab reports. They would also be required to demonstrate the ability to perform all calculations leading to reported results regardless of what the technology is able to calculate for them. Giving them access to automatically calculated results in the database/lab interface program is akin to having the answers in the back of the book – the number is known, but they must know how to get to that number.
The system I imagine would give the students not just the “answers” but also the ability to run hypothetical experiments - I’m building some Excel spreadsheets (”toys”) for this purpose. With these, they will gain a tool to help them critically evaluate why the results change as they do when an error occurs or when a procedure is altered.
In the development of this lab model, some questions will need to be addressed such as: What is the role of prelab lectures in a model that emphasizes post-lab lectures?; Is there a way to enhance the use of traditional notebooks within the proposed technology?; What role should online student collaboration play?; Can the technology be made to enhance in-lab collaborations? Feel free to add more…