The other day in my Biology classes, my lesson plans included discussing controlled experiments and identifying variables. (I know, exciting stuff!) In my first decade of teaching it was a struggle to get kids to tell the difference between the independent variable and the dependent variable. I was proud of developing a tool to help them in this quest and always begin the year telling kids “if you use 'To see if _____________ affects _____________,' format it will be easier to keep them straight. The first blank is the independent or manipulated variable, and the second is the dependent or responding variable. It comes in extra handy when writing lab reports. If you see the purpose statement as the question you are trying to answer, then the conclusion is the answer to that question, supported by data."
For example: To see if discounts affect shopping habits.
Independent variable: discounts; dependent variable: shopping habits.
Conclusion: Yes, discounts affect shopping habits because when Lord and Taylor has a sale and email coupons, Ms. K always goes shopping.
Well, for kids I use other examples, like to see if amount of sleep affects student performance, but you get the point.
At the end of the day, at the end of my first week of teaching, I found that all my students knew the difference, that even if I changed sentence structure to be tricky so that the independent variable was not found in the first half of the sentence, students identified them correctly. Not one student got one wrong. In any of my three sections of Biology! Can I tell you how happy I was? Beyond that, they know what a control is, and what constants are. They can discuss controlled experiments like it’s nobody business. I am thrilled.
The victory belongs to my colleagues, of course, who get these students before me, in freshman biology, or at the middle school. But it makes me happy nonetheless. I am hopeful that they’ll grow up to be scientifically literate adults. That they’ll be able to analyze and think critically and be savvy consumers. But right now it’s enough to be hopeful that we will have a good year.
Little victories first.