Sep 10, 2012

Too Many Factors Beyond Our Control

The Chicago teachers are on strike today. I am sad that they were not able to negotiate a contract and that it had to come with this. I do see both sides, really. I read articles from both sides, to make sure I wasn't just reading one slant.

Here's a passage that stood out for me:

“Another concern is evaluation procedures. After the initial phase-in of the new evaluation system it could result in 6,000 teachers (or nearly 30 percent of our members) being discharged within one or two years. This is unacceptable. We are also concerned that too much of the new evaluations will be based on students’ standardized test scores. This is no way to measure the effectiveness of an educator. Further there are too many factors beyond our control which impact how well some students perform on standardized tests such as poverty, exposure to violence, homelessness, hunger and other social issues beyond our control."
 There was a 4th grade boy who was struggling over a "practice test." I was helping him, without feeding him the answers. One set of questions was analogies. "Yellow is to lemon as green is to ____." He must have spent 10  precious minutes, even with my help and hints and explanation, to understand what the question was asking for. He just didn't know. When I finally told him the answer so that we could move on to the next question, he asked, "what's a lime?"

This child had never seen a lime, did not have a clue about its similarity to a lemon, did not know what color it was; it was just not something that was part of his culture. He never would have answered that question correctly.

Should the teacher be evaluated poorly for that?

Striking for reasons of extortion and greed is one thing. Getting a poor evaluation / losing one's job because of factors beyond your control just seems wrong. Am I right?

Sep 1, 2012

Math Lesson From a Hurricane

According to something called Live Science, Mobile AL tops the list of soggiest cities. Really? Then how do you explain our high water bills from years of having to water our grass? It has to do with statistics. Ah, you knew there'd be math involved, didn't you?

Mobile's weather patten, according to my completely unscientific observation, usually looks something like this: drought, drought, drought, drought, hurricane.

For ease of calculation, let's say that each drought year brings just 30 inches of rain, and the hurricane year dumps 100.  (These are not the actual numbers!)

Mean: add them up and divide by the number of years you're counting.
     30 + 30 + 30 + 30 + 100 = 240
     240 / 5 = 48
     Mean = 48

Median: line them up numerically from smallest to largest, and select the one in the center.
    30, 30, 30, 30, 100.
     Median = 30

Mode: the most popular. Which number occurs most frequently? 
     Mode = 30

Mode, when talking about rainfall on a community, is the only statistic that matters to a homeowner. I want to know what to expect. Usually, we're going to have to water our lawn. Once in a while, a hurricane will come along and do it for us. 


Statistics can say anything you want them to. If you want to say that our "average rainfall is 67 inches," you can find the data to back up your claim.

But don't try to sell it to me. I know better. I pay the water bill.