Purpose statements
A very dark side of the so-called 'scientific method' as it is taught in high schools is to encourage students to write purpose statements. And what's disappointing here is that this is creeping into the college level, and it seems as though (or am I just becoming pessimistic?) I have to be increasingly diligent to break students of this practice.
There are two problems here in my view.
The first is pedagogical. What I see is that when students write a purpose statement, independent thinking suffers. Beginning a sentence with 'the purpose of this lab was...' is to put mental blinders on. It's a very constraining way to understand an experiment (more on that below). But deep down I have to wonder if it doesn't make us all regress a little bit to a high school or middle school science class state of mind and forget for a moment that we are independent minded adults. I worry (and as I said in the last post - this is anecdotal and don't ask me for the research on this because there ain't none) that students are taught the purpose statement as a rote crutch, an obligatory part of form-based lab reports.
My justification for this first point is anecdotal but powerful. I always remember the looks of surprise I get from a few students every year at the beginning of lab when I tell them purpose statements are forbidden. Some still insist on it - certain I can't be serious. And then I can compare. Students breaking free of the purpose statement show me more independent thinking in the abstract and lab reports. Students clinging to the need to do a purpose statement against all requests give rote descriptions of the equipment and methods.
One other pedagogical comment: when I see a purpose statement it almost always turns out that the student had unusual difficulty understanding the experiment and so I think they reverted to the purpose statement as a crutch.
The second problem is that a purpose statement is an empty comment that loses sight of the analysis and the context of the study. Going back to our purple deer, I think in high school or earlier students are encouraged to write something like, "The purpose of this experiment was to make field measurements of deer colors." But this statement is terribly incorrect. Measuring deer colors was just a method, a tool of the study. Measuring deer colors merely provided data that was analyzed to try to answer interesting questions. The purpose statement encourages students to passively recite the methods and to lose sight of the real prize: the opportunity to perform critical and independent and creative analysis of the results.
Say that you're a food critic and you just visited a restaurant where the food was awful and you can't wait to write a masterpiece of scathing critique. Would you write,'The purpose of my visit to the new french bistro in town was to repeatedly place the food in my mouth and sample it across my palette using standard eating utensils."? While it may be easier to recognize that this is absolutely ridiculous, it is just as bad as the purpose statement above on purple deer. This is why purpose statements never appear in any peer reviewed scientific literature.
Look - I have to admit that this is all part of what we do to nurture students along. Before college they start off with purpose statements to develop initial skills in thinking about science, but then we need to transition them out of it in order to reach the next level of doing science. At the college level we are in the role of facilitating that very important transition. What I'm wondering is if - when we think about what we can do to try increase the scientific prominence of our educational system - we shouldn't be looking more critically at some of the pedagogical tools that are not serving us well. My worry is that we have canonized a poor view of the 'scientific method' that should be rethought.