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beza1e1
beza1e1
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beza1e1
beza1e1
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I just read: http://www.r-statistics.com/2010/02/post-hoc-analysis-for-friedmans-test-r-code/

Here is the example from the blog post:

Let’s make up a little story: let’s say we have three types of wine (A, B and C), and we would like to know which one is the best one (in a scale of 1 to 7). We asked 22 friends to taste each of the three wines (in a blind fold fashion), and then to give a grade of 1 till 7 (for example sake, let’s say we asked them to rate the wines 5 times each, and then averaged their results to give a number for a persons preference for each wine. This number which is now an average of several numbers, will not necessarily be an integer).

Why let them rate the wine "5 times each"? This is just an arbitrary number. More importantly, how do you know that "5" is enough? How should you define "enough"? Is "4" or "2" also enough? Are there methods to quantify how good a sample size is?

For my personal problem, I have to test with datapoints, where the mean is around 100 and the standard deviation is 300. This is averaged over 500 samples, but is this enough, for such a huge variance?

I just read: http://www.r-statistics.com/2010/02/post-hoc-analysis-for-friedmans-test-r-code/

Here is the example from the blog post:

Let’s make up a little story: let’s say we have three types of wine (A, B and C), and we would like to know which one is the best one (in a scale of 1 to 7). We asked 22 friends to taste each of the three wines (in a blind fold fashion), and then to give a grade of 1 till 7 (for example sake, let’s say we asked them to rate the wines 5 times each, and then averaged their results to give a number for a persons preference for each wine. This number which is now an average of several numbers, will not necessarily be an integer).

Why let them rate the wine "5 times each"? More importantly, how do you know that "5" is enough? How should you define "enough"?

For my personal problem, I have to test with datapoints, where the mean is around 100 and the standard deviation is 300. This is averaged over 500 samples, but is this enough, for such a huge variance?

I just read: http://www.r-statistics.com/2010/02/post-hoc-analysis-for-friedmans-test-r-code/

Here is the example from the blog post:

Let’s make up a little story: let’s say we have three types of wine (A, B and C), and we would like to know which one is the best one (in a scale of 1 to 7). We asked 22 friends to taste each of the three wines (in a blind fold fashion), and then to give a grade of 1 till 7 (for example sake, let’s say we asked them to rate the wines 5 times each, and then averaged their results to give a number for a persons preference for each wine. This number which is now an average of several numbers, will not necessarily be an integer).

Why let them rate the wine "5 times each"? This is just an arbitrary number. More importantly, how do you know that "5" is enough? How should you define "enough"? Is "4" or "2" also enough? Are there methods to quantify how good a sample size is?

For my personal problem, I have to test with datapoints, where the mean is around 100 and the standard deviation is 300. This is averaged over 500 samples, but is this enough, for such a huge variance?

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beza1e1
beza1e1
  • 249
  • 1
  • 2
  • 6

How many samples is enough?

I just read: http://www.r-statistics.com/2010/02/post-hoc-analysis-for-friedmans-test-r-code/

Here is the example from the blog post:

Let’s make up a little story: let’s say we have three types of wine (A, B and C), and we would like to know which one is the best one (in a scale of 1 to 7). We asked 22 friends to taste each of the three wines (in a blind fold fashion), and then to give a grade of 1 till 7 (for example sake, let’s say we asked them to rate the wines 5 times each, and then averaged their results to give a number for a persons preference for each wine. This number which is now an average of several numbers, will not necessarily be an integer).

Why let them rate the wine "5 times each"? More importantly, how do you know that "5" is enough? How should you define "enough"?

For my personal problem, I have to test with datapoints, where the mean is around 100 and the standard deviation is 300. This is averaged over 500 samples, but is this enough, for such a huge variance?