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I want to compare two tools, A and B.

I use tool A to measure 10 very different objects, making 5 repeated measurements for each object so I can record an accurate value.

I also do this with tool B.

Now I have some options:

  1. Average each 5 replicate measurements and do a single paired t-test. But there must be some error in each measurement set (5 replicate), so how do I account for this error?
  2. Do a separate t-test for each object. Let's say I can only reject the null hypothesis for some objects but not others. (And I don't know what aspect of the specific object affects the result.) How would I aggregate the result to get an overall comparison of A vs B?
  3. Do an ANOVA test. But in this case I only care about two categories, I don't know if ANOVA is appropriate.
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  • $\begingroup$ Selection of an appropriate procedure depends in part on what you expect of the measurement dispersions: should they be approximately the same for every object? Or, perhaps, would you expect them to be proportional to each object's true value? $\endgroup$
    – whuber
    Commented Apr 4, 2022 at 20:23
  • $\begingroup$ I expect the mean of the 5 replicates is very different for each object. Which procedure is then suitable for each case? a) the distribution of the 5 replicates is very similar, just around a different mean for each object, b) the distribution of the 5 replicates is different for each object due to random noise? $\endgroup$
    – jndi75
    Commented Apr 4, 2022 at 20:40
  • $\begingroup$ It sounds like you are trying to perform a gage R&R study. I suggest searching on that topic. $\endgroup$
    – Dave2e
    Commented Apr 4, 2022 at 23:03

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