version 22.012
New: Comparison of trimmed means of paired samples
New: Yuen-Welch test for the comparison of 2 independent trimmed means.
Computional notes are given on Calculation of Trimmed Mean, SE and confidence interval
Revision of the definition of "percentage trimmed":
In previous MedCalc versions, for a 20% trimming, the program would trim 10% at the lower tail and 10% at the higher tail, so 20% in total. This was in agreement with Excel
In the new MedCalc version, for a 20% trimming, the program trims 20% at the lower tail and 20% at the higher tail, so 40% in total. This is in agreement with SPSS, R and other major statistical packages.
For the summary statistics report, when recalling older analyses, MedCalc will adapt the % value of the trimmed mean. When you selected a 20% trimmed mean in the old version, the report will show that this is now called a 10% trimmed mean. The reported trimmed mean will remain the same. For new analyses, the new definition will be applied automatically.
For the trimmed mean spreadsheet functions there will be no conversion and the calculated trimmed mean will always be that corresponding to the revised definition. The calculated trimmed mean will be different.
