Confidence Interval For Tmax [Nonparametrics]
Hi Mohamed,
first of all, please read this post and follow the forum’s policy (you confirmed with the registration that you have read and accepted it)! I had to edit all of your posts…
tmax comes from an ordinal scale and therefore, follows a discrete distribution (dependent on the sampling schedule). Hence, a nonparametric analysis is correct in principle. However, transformations are only allowed for data coming from a ratio scale (continuous with a true zero point).
Therefore, the report you found is crap. SAS is a fine piece of software but only as good as the user. This one probably was not qualified for his/her job.
Common language will give you a hint whether an additive model (raw data) or a multiplicative model (log-transformed data) should be used. Every time you say “X is Y% of Z” or “X is Y% lower than Z” you should apply a log-transformation (e.g., Cmax). If you say “the difference of X to Z is Y” you should use the raw data (e.g., tmax).
first of all, please read this post and follow the forum’s policy (you confirmed with the registration that you have read and accepted it)! I had to edit all of your posts…
❝ […] However, I found a SAS report that generate a Non parametric analysis test on Ln transformed Tmax;
tmax comes from an ordinal scale and therefore, follows a discrete distribution (dependent on the sampling schedule). Hence, a nonparametric analysis is correct in principle. However, transformations are only allowed for data coming from a ratio scale (continuous with a true zero point).
Therefore, the report you found is crap. SAS is a fine piece of software but only as good as the user. This one probably was not qualified for his/her job.
Common language will give you a hint whether an additive model (raw data) or a multiplicative model (log-transformed data) should be used. Every time you say “X is Y% of Z” or “X is Y% lower than Z” you should apply a log-transformation (e.g., Cmax). If you say “the difference of X to Z is Y” you should use the raw data (e.g., tmax).
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Helmut Schütz
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- Confidence Interval For Tmax Mohamed Yehia 2017-07-29 22:10
- Confidence Interval For Tmax ElMaestro 2017-07-29 23:30
- Confidence Interval For Tmax Mohamed Yehia 2017-07-29 23:38
- Confidence Interval For TmaxHelmut 2017-07-30 14:41
- Confidence Interval For Tmax Mohamed Yehia 2017-07-29 23:38
- Confidence Interval For Tmax ElMaestro 2017-07-29 23:30