Sunday, August 9, 2009

Standards Sundays: Grade 5 statistics, data analysis, and probability

Will I bet on luck or probability?

Whenever I think of psychology, I never think it is a science and I've gotten into heated discussions with people where I always end up as the only one who doesn't think it should be classified as a pure science. Of course it has aspects of science in it, but it's more somewhere in the middle between science and social science I think.

Similarly, whenever I think of statistics, I never think of it as a pure mathematical subject. It's something in between as well; and thus I again end up being the only person thinking this way. It gets rather "me-against-the-world," which can be too emo for my tastes, so I've grown to stop initiating these discussions but I'll still stand my ground when it's unavoidable.

In fifth grade statistics, data analysis, and probability, students are expected to:

- know what mean, median, and mode means, how they can sometimes be different values, and how to calculate them
- read graphs and charts, as well as know how to organize data into a suitable graph/chart for the data given
- know how to compare data sets of different sizes (i.e. 20% of 19 and 20% of 900 is different how?)
- interpret meaning from graphs (i.e. positive and negative correlations), which incidentally is another way to use functions

Everything here is pretty straightforward. I find that sometimes students can be most confused with the data itself. What is data? How does data come about? What happens with the anomalies and outliers? Speaking of which, I really want to read that book about outliers but have yet to find it available at my local library.

Most of all, I think students have trouble grasping what all this "data about data" have to do in real world application? It's easy to say that the average price of milk from ten different stores in one town is $2.89 per gallon. But how on earth is this useful? Why would people spend the time calculating this stuff if its usefulness isn't apparent? And why would a store make a gallon of milk $4 when all the other stores are selling it at $2? Most baffling of all, why do some consumers have a greater desire to by the more expensive milk when they can get the same thing at half the cost?

See, it's not a degrading thing to be an "in between" subject like psychology or statistics. In my arguments (yes, I finally admit they are arguments), I never have once said that one subject is "superior" to the other (whatever "superior" means anyway). Pure math is not better than statistics. People just assume that. Which means in their minds, pure math IS better than statistics. Which is maybe why they get so defensive about it.

And once again, I've created a post that doesn't really make sense. How on earth did it get to be this way? The summer brain drain has its affects on me too, not just on students.

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