DESTINATION COMPATIBILITY, AFFORDANCES, AND CODING RULES - A REPLY

Proctor, Van Zandt, Lu, and Weeks (1993) argued that the invocation of affordances to explain stimulus-response (S-R) compatibilities in reaction time is not needed because left-fight direction compatibility, from the coding rules approach, explains the apparent ''destination compatibility'' effect of Michaels (1988). In this reply, an experiment demonstrates that destination compatibility can be shown even when contradicted by relative left-right motion. The second half of the article addresses theoretical issues separating and joining these two approaches. It is argued that the domain of the affordance approach in S-R compatibility is the guidance of action by information, whereas the domain of coding rules is S-R incompatibility and noncompatibility, situations in which required responses are not afforded and rules must be invoked. The manipulation of rules can mimic some of the consequences of more fundamental perception-action couplings, but principles of the latter sort are needed.