“High correlations with comparable scales of other instruments” seems to be an odd metric to demand—is there some reason this would imply a flaw in Myers-Briggs rather than a flaw in the other instruments or simply that they’re measuring different things?
The second paragraph’s criticism that Myers-Briggs scores aren’t bimodal is something I find even more baffling. I wouldn’t have expected any accurate test of non-sexual human behavior to show bimodal results, but I would expect the results of any test to be oversimplified into “you’re more/less X than average” categories.
The Forer effect probably is a significant factor in people’s appreciation of Myers-Briggs, though. And the criticism of its dependence on honest self-reporting hits close to home: when I took a few versions of the test long ago, I found that where I fell on the J/P scale seemed to be heavily determined by what fraction of the questions were phrased as “do you try to X” versus “do you typically X”.
is there some reason this would imply a flaw in Myers-Briggs rather than a flaw in the other instruments or simply that they’re measuring different things?
This is the usual modus tollens/ponens question: just pointing out inconsistency (low correlation) doesn’t tell you who to favor. In this case, the argument for rejecting MBTI rather than the others would go something like ‘it has a highly questionable origin and does not seem to measure anything interesting; the other scales have good theoretical justifications in their areas or were derived directly from the data, have demonstrated various forms of usefulness like predicting relevant behavior, and are less likely to be collectively wrong than MBTI uniquely correct’
As for measuring different things, well, then you get into other things like the lower psychometric reliability of MBTI compared to Big Five—if a instrument is not reliable, then it may be measuring nothing of interest.
“High correlations with comparable scales of other instruments” seems to be an odd metric to demand—is there some reason this would imply a flaw in Myers-Briggs
“High correlations with comparable scales of other instruments” seems to be an odd metric to demand—is there some reason this would imply a flaw in Myers-Briggs rather than a flaw in the other instruments or simply that they’re measuring different things?
The second paragraph’s criticism that Myers-Briggs scores aren’t bimodal is something I find even more baffling. I wouldn’t have expected any accurate test of non-sexual human behavior to show bimodal results, but I would expect the results of any test to be oversimplified into “you’re more/less X than average” categories.
The Forer effect probably is a significant factor in people’s appreciation of Myers-Briggs, though. And the criticism of its dependence on honest self-reporting hits close to home: when I took a few versions of the test long ago, I found that where I fell on the J/P scale seemed to be heavily determined by what fraction of the questions were phrased as “do you try to X” versus “do you typically X”.
This is the usual modus tollens/ponens question: just pointing out inconsistency (low correlation) doesn’t tell you who to favor. In this case, the argument for rejecting MBTI rather than the others would go something like ‘it has a highly questionable origin and does not seem to measure anything interesting; the other scales have good theoretical justifications in their areas or were derived directly from the data, have demonstrated various forms of usefulness like predicting relevant behavior, and are less likely to be collectively wrong than MBTI uniquely correct’
As for measuring different things, well, then you get into other things like the lower psychometric reliability of MBTI compared to Big Five—if a instrument is not reliable, then it may be measuring nothing of interest.
This is how you typically meassure test validity.