NewBuyer;572018 Wrote: > I think you are certainly doing better now, with this last proposal. No > longer is there a subjective "better" involved in the research > hypothesis, but rather a more realistic test of a detected > "difference". Also using different songs for different trial pairs > will in fact allow a more realistic approximation to the > independence-of-trials requirement - particularly if the test subject > is NOT involved in the choice of songs used. I believe you could still > benefit the test structure further by doing a two-sided test here - > otherwise your P-values will likely be too artificially low. Also, if > you are trying to establish that detection success is generally more > likely than merely random selection, you absolutely would need to > utilize randomly selected subjects, and definitely more test subjects > than just one (even if that one is John!) :)
Thanks, agree generally, but specifically: - Different songs are not required, but may be preferred. Independence is provided by random pairs of songs that are the same format or different formats, even if all the pairs are the same song. - It should be one tailed as to prove he hears a difference he has to correctly identify difference or sameness in enough cases. If he often states the opposite of what the reality it will certainly be strange but it would mean that he couldn't hear the difference in pairs that were in fact different. - I think the H0 should be expanded that nobody can hear the difference on any song. H1 in this case (assuming John as subject) is that John can hear the difference on songs he chose. It would of course be better to do this on more subjects though, but it does have to be on people who claim they can hear a difference. If I don't think I hear the differences I cannot take these tests. I think most of the lossless is lossless camp believes nobody can hear any difference on any song. So a reasonable alternative is someone can hear some difference on some songs. I think I'll set up a spreadsheet to help people set this and check the result. -- lrossouw Louis 'Last.fm' (http://www.last.fm/user/lrossouw) ------------------------------------------------------------------------ lrossouw's Profile: http://forums.slimdevices.com/member.php?userid=3416 View this thread: http://forums.slimdevices.com/showthread.php?t=71321 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
