Gifted Issues Discussion homepage Forums Learning Environments How to teach what the mean is with data analysis

My DS7 is working on a project for the school science fair. He is testing the Stroop Effect, specifically the difference in times between kids and adults. He has done a great job collecting the data and has had fun learning how to use an Excel spreadsheet. Today though I tried to explain how he could get the "average" (mean) of each group. He understood the formula, in terms of adding all the numbers and dividing by the number of subjects. The adults had 16 subjects and the kids 15. So when he looked at the difference in means from each group, his conclusion was that the difference occurred because there was one less kid.

Do you know of any websites or other resources that do a good job of explaining this concept in a kid friendly way? Or is this just too high a level of concept and I shouldn't expect that he should get it? (He works at about a 3rd grade level in math and understands multiplication and division well. So far he's understood everything I've thrown at him.)

Thanks in advance for your help!

I don't know if this would help, but I'd have him add in one more data point for a fictional adult and see that it doesn't make the means the same just b/c there are the same # of subjects in each group now. I have no idea what your # are, but let's say that the adult mean is 20 and the child mean is 30. I'd pick another # for fictional adult#1 (something like the mode or another #s that is well within the typical range for the adults he tested). Have him recalculate the mean with that fictional #.

Perhaps seeing that his conclusion doesn't work out might get him seeing your point. He could then (if interested) play around with sets of #s with the same # of data points in them but different # for each data point and see how having the same overall # of scores doesn't create the same mean if the scores themselves are different. Does that make any sense?

I think Cricket's suggestion is an excellent one. Eliminate the thing that is causing him to draw an erroneous conclusion (for now).

I'd probably also make piles of pennies representing the money of several fictional individuals and have him calculate their "average" wealth and then redistribute the piles so that they all have the same (average) amount. Have to make sure you start with a total number of pennies that is a muliple of your number of fictional people.

Finally, I would use the word 'average' in conversation frequently, even if it's a situation where it's not exactly mathematically correct.

You might try this lesson on averages. Khan Academy has it listed as a lesson under algebra.



My ds7 loves the videos from this site.

Thanks everyone for your wonderful suggestions!!!