Repetition, Probability and Statistics: The Importance of Making Multiple Measurements
This week students learned about statistics (the science of making sense of lots of numbers). We tried to use normal distributions to draw conclusions from data. A normal curve, also called a bell curve, is a distribution of data seen many places in nature. Scientists use normal curves to analyze data, and teachers may use a bell curve to determine what grade to give a student. The students had a lesson illustrating the importance of making multiple measurements when you’re doing a science experiment — such as a science fair project!
Students enjoyed trying to figure out, on our miniature “Plinko board”, which of three holes in the top of the board all the balls were dropped through, while the top of the board was covered. Using the game board, they collected data that shows the more data you collect the closer to normal the curve becomes. If a phenomenon we are observing matches the bell curve, it lets us make certain predictions about future measurements.
Students then used coin-flipping to add normally distributed “errors” to an assigned “true value”. They then exchanged these simulated “measurements” with another group, and attempted to determine each others’ “true value” by making a histogram of the “measurements” and assuming they were normally distributed. It was interesting to notice the variability in all the different sets of “measurements” — some were much easier to interpret than others! Sometimes 10-20 measurements aren’t enough to get a clear answer!