Wednesday, May 11, 2011

Zoya Mitzi

If anyone ever needs the concept of a related-samples t-test explained -- or needs a related-samples t-test computed -- I am SO your gal. Just gave a boring lecture on it in stats yesterday. The PowerPoint took me over ten hours to create (though only thirty minutes to deliver). Maybe I shouldn't explicitly do every little calculation next time...?

Zoya Mitzi

Such a fun color, no? Grass green creme, with a satin finish. It's not quite matte-matte but still not quite shiny. It was a hard polish to put on. I needed three thick coats to get it to the smoothness you see in this photo (i.e. not smooth). BUT it lasted forever, which is totally contrary to my experience with mattes: I put it on one day thinking that it'd chip the next day and then I'd change my polish. But no... it clung to my nails for four days without a single chip. I only took it off because I was sick of the color. And the non-smoothness.

I had the most aggravating exchange with a student in section the other day. Sometimes, it's really hard to maintain a helpful attitude.

The scene: a classroom full of students bent studiously over a worksheet on using z- and t-tests. Everyone hard at work... except for one student who is doing nothing and looking bored. I ask him what exactly he doesn't get -- thinking that he's probably unclear about when to use a t-test and when to use a z-test -- and he asks in return, "What's a z-score?"

This is not a stupid question. Most people don't know what a z-score is. HOWEVER, it's something we started learning and using in early April. Since then, z-scores have been front and center in every lecture, homework and worksheet until about a week ago when we started talking exclusively about t-statistics. And it's not that this student has been absent... he's been in lecture, section and turns in work.

I explain z-scores to him briefly. He nods. I add that it's nothing to freak out about; we've been using it for weeks. Same ol' z. If you have the value of an area under the normal curve, you can find the corresponding z score in the same ol' z table.

Student: What's a z-table?

flinty: The table we've been using for the past three weeks. [I try to explain what the table looks like, thinking it'll jog his memory.]

Student: Where do I find that?

flinty: It's in the textbook.

Student: Oh.

flinty: [waits for student to open the textbook]

Student: [not opening the textbook]

flinty: Do you want to go to the z-table and I can walk you through the process of finding the z-score?

Student: OK. [still doesn't open the textbook]

flinty: Why don't you open your text to the z-table so we can get started?

Student: Where in the book is it?

flinty: It's in the back.

Student: [flips through a few pages in the front of the book] I can't find it.

flinty: Just flip through the last twenty pages or so. It's there.

Student: [opens the last page of the textbook and stops]

flinty: [waits]

Student: Can you find it for me?

flinty: Uh... sure. [finds the table and puts the book down on his desk]

Student: So what do I do now?

flinty: [walks him through the whole problem and eventually points out the answer]

Student: OK. So what do I do now?

flinty: The next problem. [pause] It's similar to the one we just did so don't close the book.

Student: [doesn't even look at the problem] I don't get it.

He had to have been pulling my leg, right? RIGHT?