Transfer Appropriate Practice in Visual Search .

1. Transfer Appropriate Practice in Visual Search. & Richard A. Abrams William H. Knapp III Washington University in St. Louis Istanbul Şehir University The Differences (Between-Participants) Effects in Error Rates Abstract Target X Block Targets Distractors Targets and Distractors were orthogonally combined. 16 participants participated in each combination. Response keys, target and distractor exemplars, and the order of the exemplars were counterbalanced. Target Presence X Target Practice often improves performance, but not all types of practice are equally beneficial. In a visual search task, participants showed practice benefits when searching for the same objects, for the same type of objects, and through the same distractors. These benefits, however, varied in their magnitude and temporal duration. Same: Different: New: Practice=Knives Practice=Knives Practice=Tweezers Test=Same Knives Test=Different Knives Test=Knives Early same and different advantages over new targets. Greater effect of target presence for new targets. Same: Different: Practice=Distractors Practice=Distractors Test=Same Distractors Test=Different Distractors A Brief Background People routinely search for particular objects (targets) hidden amongst other objects (distractors). Practice improves search performance (McCarley, Kramer, Wickens, Vidoni, & Boot, 2004). . Could indicate a speed-accuracy tradeoff. However, see Zenger and Fahle (1997). Additionally, the main effect of target was significant. F(2,90)=5.0, p<.01. Distractor Same distractor advantage over different distractors. Effects in RTs Target Presence X Target X Block: Early same advantage over different that disappears after the first test block. Long lasting same advantage over new that doesn’t disappear until the last test block. Long lasting different advantage over new for target present trials only. Other Effects What Types of Practice Transfer? Target Presence F(1,90)=126.1, p<.001 Target Presence X Block F(4,360)=3.5, p<.01 Practice with the same targets? Practice with the different target exemplars? Practice with the distractors? Target Presence X Distractor X Block: All error bars represent 95% Within-Participants Confidence Intervals (Jarmasz & Hollands, 2009) Conclusions Greater effects of target presence for different distractors in earlier test blocks. The Common Task (Within-Participants) • Practice with the same and different targets helps. • Practice with the same distractors helps. • Not all types of practice are equally beneficial. • Switching to searching for new targets incurs major costs. • Different distractors are especially distracting when the target is absent. Is there a knife*? Lower Order Effects: 96 Participants 120 Trials Per Block 1/2 Target Present 1/2 Target Absent Randomized 5 Practice Blocks 5 Test Blocks Target Presence Target Block PresenceXBlock BlockXTarget BlockXDistractor F(1,90)=263.3, p<.001 F(2,90)=4.4, p<.05 F(4,360)=86.2, p<.001 F(4,360)=41.8, p<.001 F(8,360)=9.7, p<.001 F(4,360)=7.3, p<.001 References: Jarmasz, J. and Hollands, J. G. (2009). Confidence intervals in repeated measures designs: the number of observations principle. Canadian Journal of Experimental Psychology, 63, 124-138. McCarley, J. S., Kramer, A. F., Wickens, C.D., Vidoni, E. D., and Boot, W. R. (2004). Visual skills in airport-security screening. Psychological Science, 15, 302-306. Zenger, B., & Fahle, M. (1997). Missed targets are more frequent than false alarms, a model for error rates in visual search. Journal of Experimental Psychology: Human Perception and Performance, 23, 1783-1791. * See “The Differences”