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Critical value
Message posted by Drema (via 206.105.202.241) on June 18, 2001 at 11:27 PM (ET)
Help!
A sample of 8 students was selected to test the effectiveness of a course for typing skills. Scores before and after given below.
alpha = 0.01
before: 45 38 60 35 70 48 39 49
after: 56 42 62 39 75 50 42 56
What is the critical value and how do I calculate this value?
READERS RESPOND:
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Re: Critical value
Message posted by JG (via 128.8.22.74) on June 19, 2001 at 6:45 AM (ET)
Re: Critical value
Message posted by JG (via 128.8.22.74) on June 19, 2001 at 7:03 AM (ET)
If you assume normality and use a paired, matched sample test then t(.01,7)=3.0 - one sided and t(.005,7)=3.5 - two sided.
For the Wilcoxon rank test for two paired samples, you generate a t-statistic from the signed ranks of differences and then use a t-test.
For the Wilcoxon rank test you need not have matched samples or even samples of the same size and you use the W-statistic for which special tables exist.
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