Distinguishing ordinal and disordinal interactions
Psychological Methods (2012) - Comment
pubmed: 22984788  doi: 10.1037/a0030003  issn: 1939-1463  issn: 1082-989x 

Keith F. Widaman, Jonathan L. Helm, Laura Castro-Schilo, Michael Pluess, Michael C. Stallings, Jay Belsky