I know a similar question was asked before, but please help me to apply this to my model:
1. test two regressions - A versus B and A versus C (similar observations n=1242)
2. Model A versus B has an higher Rsquare and seems to have a better correlation - but a Lack of fit < 0.05
3. Model A versus C has a lower Rsquare and sems to have a bit less correlation - but a lack of fit > 0.05
4. The residual plot looks quite similar.
For the actual full result please see also my attached PDF.
My question: Do I have to disregard Model A versus B and conclude that A versus C is better and more appropriate for my analysis ?
Based on a brief glance of the models my feeling is that you are worrying too much about the detailed statistics. The 2 models look almost identical to me (look at the bivariate plots not just the stats) - clearly there is a very high level of correlation between B and C. Does your scientific understanding favour one model over another?
What stands out to me are the high leverage points at a value of about 70 (for both B and C - strange that they are both on the same scale - are they different measures of the same thing?). Anyhow, I would be concerned about the degree of leverage of those points and their overall influence on the regression.