F / 
instructions asked subjects to list "examples" of things 
they owned and of things they did not own. One subject 
asked if the point was to list a variety of different sorts 
of things, rather than things that just come to mind. On 
the third section of the questionnaire, subjects were asked 
to judge the criteria as general arguments for ownership. 
The instructions used the wording "arguments or 
justifications for ownership", which was apparently 
interpreted by some subjects as, "reasons I choose to own 
something” instead of "reasons upon which I base claims of 
ownership". This may explain why the criteria Aesthetics 
and Desire were ranked ahead of Territoriality, Familiarity, 
and Knowledge in this study, but behind them by two groups 
of subjects in a pilot study (See Appendix B.). The wording 
problems discussed here are a few that were identified once 
the study was in progress. Certainly, some degree of bias 
and "noise" has been introduced by such variable 
interpretations of critical terminology. 
Other sources of bias and "noise" were the 
self-selection processes by the subjects. For example, 
subjects self-selected participation. Based on comments by 
those who decided not to participate, the results of this 
study represent those who were agreeable to impositions on 
both their time and privacy. Subjects also self-selected 
the recall conditions of experimenter-present or