Getting some odd results that means either I misunderstood something fundamental early on in my stats training (and am still misreading it in the book I have in front of me), or SPSS is doing something weird and/or buggy in its background calculations.
My understanding of multiple regression has always been that if you are, say, regressing predictors X and Y on criterion Z, the results for X should be identical to what you would get if you regressed Y alone on criterion Z, saved the residuals, and then regressed X on those residuals.
From running these analyses, they seem similar, but not at all equivalent. Differences are too great to attribute it to rounding. I've checked pretty much every assumption I can think of and nothing weird is going on with the dataset. Any ideas?
My understanding of multiple regression has always been that if you are, say, regressing predictors X and Y on criterion Z, the results for X should be identical to what you would get if you regressed Y alone on criterion Z, saved the residuals, and then regressed X on those residuals.
From running these analyses, they seem similar, but not at all equivalent. Differences are too great to attribute it to rounding. I've checked pretty much every assumption I can think of and nothing weird is going on with the dataset. Any ideas?