Help with the right analysis tool

Good afternoon,

I am trying to compare results from 2 pieces of test equipment to see if their results are statistically different. Problem is the experiment looks like this example;

Test kit 1 Test Kit 2
Sample 1 12.62 11.97
Sample 2 13.33 14.01
Sample 3 10.55 10.87
Sample 4 15.52 15.01

All samples are 100% wool but each sample is from a different breed, type etc. So we are not comparing the means and variances of two true sets of data i.e. 20 replicates of Sample 1 on both bits of kit, so a simple t test will not help.

I am trying to understand if both bits of kit are significantly different or if the variance between results is normal so the kits could be viewed as being 'in calibration'. I suppose it is a bit like a laboratory correlation trial.

Any advice much appreciated.




TS Contributor
There are several approaches that you could take. One is the Bland Altman plot. Another is the Youden plot. You can also perform a 1-sample test for equivalency on the differences. I find the Bland Altman or Youden plot to provide more useful information.