> > > 2. Perhaps more likely, your boss may have learned > > (wrongly?) that parametric stats should not be done unless scales > > of measurement are at least interval in quality. > > I don't know if his objection was to parametric statistics per se, but he did > object to calculating means on these data, which he believes are only ordinal. > > > Search on google > > for people like John? Gaito and S.S. Stevens and for phrases like > > "scales of measurement" and "parametric statistics." > > Thanks. Will do. >
Or, do an Advanced search with groups.google among the sci.stat.* groups for < Stevens, measurement >. I think that would find earlier discussions and some references. As I recall it, no one who pretended to know much would have sided with your boss. The firmness of Stevens's categories was strongly challenged by the early 1950s. In particular, there was Frederick Lord's ridiculing parable of the football jerseys. (Naturally, psychology departments taught the subject otherwise, for quite a while longer.) Conover, et al., took a lot of the glory out of 'nonparametric tests' by showing that you can't gain much from rank-order transformations, compared to any decent scaling. That was in an article of 1980 or thereabouts. I may have seen a 'research manual' dated as recent as 1985 that still favored using rank-statistics with Likert-scaled items. I am curious as to what more recent endorsements might exist, in any textbooks at all, or in papers by statisticians. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at http://jse.stat.ncsu.edu/ =================================================================
