More fun with the Scientific Method

We continued our work today with the Scientific Method, as the students learned about why it's important (when designing and performing an experiment) to repeat the experiment more than once, and why it's important to one change one thing (or variable) when performing an experiment. We repeated an experiment we had done before - one where students held up one, then two, and finally three books as long as they could, using one arm held straight out from their side. We have now done the experiment with 4 people, and while the amounts of time each of them could hold the books up varied, it was pretty much a given that no matter which student (or adult!) it was that was holding the books, the person performing the experiment could hold up one book longer than they could hold up two books, and that they could hold up two books for longer than they could hold up three books. Next, we looked at why it was important to only change one variable, as Mikayla from our class couldn't hold up one book nearly as long as I could hold up two books - not exactly a fair comparison, was it?! After that, the students got together in their groups, and discussed why these things mattered when conducting an experiment, and answered on chart paper - here is one group's answer: