Tuesday, November 27, 2007
or Smart-ish?
So I went and showed my Stats TA my accomplishments, and it turns out that I was using the wrong test because I'm not looking at just one country, I'm looking at like 7. We haven't learned the technique that would be best for 7 different samples, but she showed me some other ones that would still give me good stuff, and it should give me results pretty similar to what I already. Lol, man! At least I showed my TA before I showed my prof. After I run the tests she showed me to do, I can go to my prof's office, show him my stuff and totally be like, "Oh yeah, I definitely knew not to do a t-test! I have 7 countries, not just one!" Statistics is lame.
Sunday, November 25, 2007
Maybe I'm Smart!
Beware, this post contains statistics.
So, for the past few weeks, after getting a 63% on my stats midterm, I've been a bit of a downer on stats. I mean, can you blame me? But I've decided maybe I'm catching on to things after all! For my deviance class, I'm doing my term paper on comparing high school students' use of alcohol and marijuana across the US, Denmark, Finland, France, Germany, Turkey, and the UK. I decided to be brave and include statistical analysis, not using an easy, pansy-pants, point-and-click statistics program, but the hardcore program we use in our stats class. After way too many hours, a few tears, some help from Chad, and lots of Skittles to boost my brain power, I came up with something cool! And I'll show you using my nifty graphs. =) Lol, humor me please.
Okay, look at this graph:
So, we're looking at the total percent of students who said they've consumed 3 or more alcoholic beverages in their lives. I didn't include the kids who said 1-2 because I don't think having one drink doesn't mean you drink. The European kids are ages 15-16, and the Americans are 17-18, so they're all underage. Turkey's definitely the lowest, but the US is pretty low too. Now, let's pull out the fancies.
I ran a t-test, and it spat this out:
One Sample t-test
data: res
t = 12.2813, df = 6, p-value = 1.776e-05
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
67.0581 100.4276
sample estimates:
mean of x
83.74286
Basically, anything outside the values 67 and 100 is significant. Turkey's at 46%, so it's significantly lower, which is good, that's what we want. But the US doesn't make the cut-off with its 77%. Well, then, let's just throw out Turkey to see if it's messing up the curve. Besides, Turkey has a whole different culture than all the others.
When we ditch Turkey we get this:
One Sample t-test
data: res
t = 28.9162, df = 5, p-value = 9.27e-07
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
82.02959 98.03707
sample estimates:
mean of x
90.03333
Yay! The confidence interval is 82-98, so the US at 77 is significantly lower than the others! That means it's low enough that it's actually worth investigating and explaining. The difference isn't just because of a goof in what students they sampled, there's some major difference in the countries and their cultures.
Alright, just one quick look at marijuana use because I found some surprising things!
Yikes, the US is way up there on the marijuana scale! We'll skip the analysis with Turkey, and just go to the good stuff:
One Sample t-test
data: res
t = 5.9831, df = 5, p-value = 0.001870
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
17.89975 44.86691
sample estimates:
mean of x
31.38333
The US, with 48% of its students having smoked marijuana is significantly higher than the other countries. That means the high percentage is so much higher than the others that it's not due to sampling error or random chance or fluke. There's something going on here, that's what the crazy t-test means. US is also significantly higher than other countries for having smoked marijuana in the last 12 months AND the last 30 days. Weird!!
So that's my project, investigating these differences. Plus, I'm trying to get prepped for my stats final at the same time. Fingers crossed that both aren't complete failures, lol.
So, for the past few weeks, after getting a 63% on my stats midterm, I've been a bit of a downer on stats. I mean, can you blame me? But I've decided maybe I'm catching on to things after all! For my deviance class, I'm doing my term paper on comparing high school students' use of alcohol and marijuana across the US, Denmark, Finland, France, Germany, Turkey, and the UK. I decided to be brave and include statistical analysis, not using an easy, pansy-pants, point-and-click statistics program, but the hardcore program we use in our stats class. After way too many hours, a few tears, some help from Chad, and lots of Skittles to boost my brain power, I came up with something cool! And I'll show you using my nifty graphs. =) Lol, humor me please.
Okay, look at this graph:
So, we're looking at the total percent of students who said they've consumed 3 or more alcoholic beverages in their lives. I didn't include the kids who said 1-2 because I don't think having one drink doesn't mean you drink. The European kids are ages 15-16, and the Americans are 17-18, so they're all underage. Turkey's definitely the lowest, but the US is pretty low too. Now, let's pull out the fancies.I ran a t-test, and it spat this out:
One Sample t-test
data: res
t = 12.2813, df = 6, p-value = 1.776e-05
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
67.0581 100.4276
sample estimates:
mean of x
83.74286
Basically, anything outside the values 67 and 100 is significant. Turkey's at 46%, so it's significantly lower, which is good, that's what we want. But the US doesn't make the cut-off with its 77%. Well, then, let's just throw out Turkey to see if it's messing up the curve. Besides, Turkey has a whole different culture than all the others.
When we ditch Turkey we get this:
One Sample t-test
data: res
t = 28.9162, df = 5, p-value = 9.27e-07
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
82.02959 98.03707
sample estimates:
mean of x
90.03333
Yay! The confidence interval is 82-98, so the US at 77 is significantly lower than the others! That means it's low enough that it's actually worth investigating and explaining. The difference isn't just because of a goof in what students they sampled, there's some major difference in the countries and their cultures.
Alright, just one quick look at marijuana use because I found some surprising things!
Yikes, the US is way up there on the marijuana scale! We'll skip the analysis with Turkey, and just go to the good stuff:One Sample t-test
data: res
t = 5.9831, df = 5, p-value = 0.001870
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
17.89975 44.86691
sample estimates:
mean of x
31.38333
The US, with 48% of its students having smoked marijuana is significantly higher than the other countries. That means the high percentage is so much higher than the others that it's not due to sampling error or random chance or fluke. There's something going on here, that's what the crazy t-test means. US is also significantly higher than other countries for having smoked marijuana in the last 12 months AND the last 30 days. Weird!!
So that's my project, investigating these differences. Plus, I'm trying to get prepped for my stats final at the same time. Fingers crossed that both aren't complete failures, lol.
Wednesday, November 14, 2007
Nap Time
Well, I hit a new low. Our graduate studies director, Karen, offered to take our cohort out for drinks at the local pizza joint (called "The Mellow Mushroom" and decorated with little 'shrooms playing instruments. Yes, it was established in the 70's). I was back in my lonely, quiet office by 5:30 pm, and I convinced myself that I was going to do Statistics homework while I was waiting for Chad to finish up at the law school at 7:00. I had my computer open, my music going, and my stats book in hand. At 6:30, I woke up with a major back cramp, marks on my face, and a little creek of drool flowing out of my mouth. I guess a couple beers really did me in, lol... (and my family just laughs...) Well, my office desk is fully christened now. I think I'll call it Adams, for my buddy Sam Adams. I won't lie, the nap was pretty refreshing (all things considered), and I guess it had to happen sometime this semester.
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