Q270
From enfascination
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Course Site: | Course Site: | ||
http://cognitrn.psych.indiana.edu/rgoldsto/courses/q270.html | http://cognitrn.psych.indiana.edu/rgoldsto/courses/q270.html | ||
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| + | ==Paired vs Ind Samples T-Test== | ||
| + | Here is another way to intuit why it is better to compare the means and variances of 12 pairs of data points than to compare the means and variances of one set of twelve to that of the other twelve. When squaring, large number grow faster than small ones. This means that values with more distance from the mean have more weight in determining the variance, since it is the square of the standard deviation. The two independent samples will inevitably have more points that are further from the two means than each paired sample will. As a result, the variance will be significantly higher, making it more likely that the variance in the estimates will be able to account for the difference in the means (which is bad). If this additional way of thinking about it makes it easier, good. Otherwise, you are fine forgetting it. | ||
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==Special Note: Location== | ==Special Note: Location== | ||
We were very fortunate to get hooked up at the Simon Hall lab, with the musical equipment, and I think I can safely say that we will be meeting there for the rest of the semester. | We were very fortunate to get hooked up at the Simon Hall lab, with the musical equipment, and I think I can safely say that we will be meeting there for the rest of the semester. | ||
Revision as of 03:59, 25 September 2009
Course Site: http://cognitrn.psych.indiana.edu/rgoldsto/courses/q270.html
Contents |
Paired vs Ind Samples T-Test
Here is another way to intuit why it is better to compare the means and variances of 12 pairs of data points than to compare the means and variances of one set of twelve to that of the other twelve. When squaring, large number grow faster than small ones. This means that values with more distance from the mean have more weight in determining the variance, since it is the square of the standard deviation. The two independent samples will inevitably have more points that are further from the two means than each paired sample will. As a result, the variance will be significantly higher, making it more likely that the variance in the estimates will be able to account for the difference in the means (which is bad). If this additional way of thinking about it makes it easier, good. Otherwise, you are fine forgetting it.
Special Note: Location
We were very fortunate to get hooked up at the Simon Hall lab, with the musical equipment, and I think I can safely say that we will be meeting there for the rest of the semester.
Part One of Class
Lab One
Assignment One
Note: The assignment was written with Mac in mind. Where it asks you to go to preferences, go instead of "Options" under "Edit" and find the Viewer tab from there. That said, the little box should be checked by default. Please provide me with clean printouts, not too much line noise if you can help it.