Knowledge used in duration judgments of two moving objects

Forty-nine undergraduates observed two cars traveling in the same direction on a CRT display for various duration. They then chose the car that they b elieved had run longer, and gave the reason for their choice. There were th ree types of tasks. Correct judgment was possible for the first type, by lo gically applying either of two pieces of knowledge about duration: ''durati on equals temporal end point minus temporal start point" (Knowledge alpha) or "duration equals distance divided by speed" (Knowledge beta). Knowledge alpha alone was useful for the second type, while only Knowledge beta led t o correct judgment for the third. Main results were as follows: (1) Undergr aduates were more likely to use Knowledge alpha than beta regardless of the types. (2) None of repeatedly making judgment, thinking about reasons for judgment, or receiving failure feedback was very helpful making participant s become aware of necessity of using Knowledge beta for the third type. (3) Only some 20% of undergraduates were able to use proper knowledge specific ally required for each type.