Psychology 357, Spring 2001 (Ss 1-4, 6-9) Effect of Word Context on Letter Identification (J. C. Johnston) SECOND ANALYSIS: LOW-CONSTRAINT versus HIGH-CONSTRAINT WORD CONTEXT Six ratings: 1(no,sure),2,3,4,5,6(yes,sure). Six rating probabilities: p1, .. ,p6; sum=1, for match trials. Seven cumulative probabilities: (P0=0),P1=p1,P2=p1+p2,..,(P6=1). Similarly, Q0, .. ,Q6 for mismatch trials. Pc=Pr{correct|match}=Pr{Hit}=1-P3, Qc=Pr{correct|mismatch}=Q3. Alc, Ahc are estimated areas under ROC's; Diff=Ahc-Alc. Bias = Pr(FA)/[Pr(FA) + Pr(Miss)] = (1-Q3)/(P3+1-Q3). DBias = Bias(High-constraint word) - Bias(Low-constraint word). *Difference from zero is reliable. ~Difference from zero not reliable. #Difference from 500 is reliable. WORD CONTEXT: LOW-CONSTRAINT CONDITION (Data * 1000) Sb P1 P2 P3 P4 P5 Pc Q1 Q2 Q3 Q4 Q5 Alc Bias 1 50 250 350 400 700 650 300 700 900 1000 1000 835 222 2 0 50 50 350 750 950 100 650 900 950 1000 936 667 3 0 100 200 350 650 800 300 800 900 1000 1000 933 333 4 50 100 250 300 550 750 400 750 900 950 1000 902 286 6 0 50 150 150 550 850 350 650 1000 1000 1000 957 0 7 50 100 100 200 400 900 350 800 950 950 950 908 333 8 0 0 100 300 500 900 250 650 950 1000 1000 975 333 9 50 50 200 300 600 800 450 850 950 1000 1000 944 200 Mn 25 88 175 294 588 825 312 731 931 981 994 924 297# Se 9 26 34 29 40 34 38 28 13 9 6 15 66 WORD-CONTEXT: HIGH CONSTRAINT CONDITION (Data * 1000) Sb P1 P2 P3 P4 P5 Pc Q1 Q2 Q3 Q4 Q5 Ahc Bias Diff DBias 1 50 150 250 400 550 750 350 600 750 800 950 810 500 -25 278 2 0 0 50 100 650 950 550 750 1000 1000 1000 994 0 57 -667 3 50 50 100 350 650 900 350 700 750 950 1000 900 714 -33 381 4 50 100 400 450 600 600 450 700 800 850 900 817 333 -85 48 6 0 50 100 350 600 900 350 700 900 1000 1000 954 500 -4 500 7 0 100 150 150 200 850 550 900 1000 1000 1000 970 0 62 -333 8 0 100 100 500 800 900 250 650 900 1000 1000 925 500 -50 167 9 0 150 250 300 450 750 300 750 1000 1000 1000 916 0 -28 -200 Mn 19 88 175 325 562 825 394 719 888 950 981 911 318 -13~ 22~ Se 9 18 41 49 63 41 39 31 39 28 13 24 100 18 140