I'm working on a program for 10.8 using ARC so there's no retain/release going on. What I'll describe is not exactly what I'm doing but will illustrate the problem. I have a Person class with 3 dates, say birthday, graduation and wedding. What I'd like to do is have that Person listed in an outline view With their name as the group and you click the disclosure triangle to get Birthday: 1/2/70, Graduation: 2/3/88, etc. Initially in Code: outlineView:child:ofItem: I would return, for instance, Code: [NSString stringWithFormat: @"Birthday: %@", [person birthday]]; However, after Code: outlineView:objectValueForTableColumn:byItem: displayed that item, the string was being released and the program would crash with EXC_BAD_ACCESS. Alternately I could return the date in Code: outlineView:child:ofItem: but how would I know what date it was in Code: outlineView:objectValueForTableColumn:byItem: ? The workaround I currently have is to have an NSMutableArray, put the string in there and then return it. The Array basically ups the retain count, it doesn't get released, all works well. But it's kind of an ugly workaround. Does anyone have any suggestions for a more elegant solution?