On 23 Apr 2002 07:58:08 -0700, [EMAIL PROTECTED] (F. Goldhammer) wrote: > Hi all, > > I want to calculate the reliability of the following quotient: > quotient=MEAN(item7, item8 ... item18 )/MEAN(item1, ... item6). The 18 > items form a time series. > Analogous to the testhalf-reliability I have devided the 18 items in > odd an even items. I have calculated the quotient separately with the > odd and the even items. At last I have interpreted the correlation [ ... ]
- Does "internal consistency" as the measure of reliability make much sense for a time series? How tightly linked are the measures? If there is a high lagged correlation, then any 'internal consistency' is foolish to think about. Before you worry about that ratio, in fact, I think the nature of the time-series needs to be worked out. Is there an external criterion for this quotient, or is it intended to predict itself-in-the-future, and nothing more? Maybe a real-life example would impress me otherwise, but what comes to mind here, in the abstract, is that a) test-retest reliability would be more convincing; and b) even more than the usual cross-sectional report, your conclusions will be heavily tied to the character of the 'sample'; however well the quotient works, that depends on various variances remaining similar. -- 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/ . =================================================================
