******************************************************************************* PROGRAM ITERLINK CONDUCTS STOCKING & LORD ITERATIVE LINKING It was written by Stephen Stark at UIUC and last revised on 05/25/00. ******************************************************************************* ITERLINK does STOCKING & LORD ITERATIVE LINKING for 2PL and 3PL models using BILOG ouptut files. The item parameter files MUST have been edited using PARTO3PL to remove first two lines and successive alternating lines. The covariance files MUST be in the exact form created by BILOG (unedited). The minimization routine was adapted from Baker's 1992 EQUATE program. A new interface was developed for iterative linking to use with routines that compute Lord's chi-square statistic. On the first iteration, you will be prompted for information about your data. Linking constants and DIF stats will be computed. Subsequent iterations will be conducted until the same items are identified as having DIF/NODIF on consecutive runs. Output will be stored in files ITERLINK.DBG and PAIRDIF.DBG. ******************************************************************************* INPUT SPECIFICATIONS AND RUN INFORMATION: -------------------------------------------------------------- Date: Day= 16 Month= 4 Year= 2001 Start Time for analyses: 21:56:23 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% INFORMATION REGARDING **EQUATING** %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% --------------------------------------------------------------- TITLE for this run: Example of Lord's chi-square analysis for 3PL model --------------------------------------------------------------- Number of ABILITY SCALE POINTS used for linking = 61 NUMBER of ITEM PARAMETERS in IRT model: 3 -------------------------------------------------------------- ** Information regarding "FROM" (focal) group ** -------------------------------------------------------------- FILENAME for "FROM" METRIC ITEM PARAMETERS: 3plfoc.3pl FORMAT for reading item parameters: (32X,2F12.2,12X,F12.6) NUMBER OF ITEMS in "from" test: 32 TEST METRIC for "from" parameters: LOGISTIC -------------------------------------------------------------- ** Information regarding "TO" (reference) group ** -------------------------------------------------------------- FILENAME for "TO" METRIC ITEM PARAMETERS: 3plref.3pl FORMAT for reading item parameters: (32X,2F12.2,12X,F12.6) NUMBER OF ITEMS in "to" test: 32 TEST METRIC for "to" parameters: LOGISTIC -------------------------------------------------------------- ** Information regarding TRANSFORMED "FROM" ITEM PARMETERS ** -------------------------------------------------------------- FILENAME for TRANSFORMED "FROM" ITEM PARAMETERS: foctran.out -------------------------------------------------------------- ** Information regarding TRANSFORMED "FROM" THETAS ** -------------------------------------------------------------- You have chosen NOT to transform thetas. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% INFORMATION REGARDING **PAIRWISE DIF** ANALYSES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Input file for FOCAL covariances: 3plfoc.cov Input file for REFERENCE covariances: 3plref.cov -------------------------------------------------------------- CRITICAL P<.05/#ITEMS (BONFERRONI) WILL BE USED TO DETECT DIF & EXCLUDE DIF ITEMS FROM COMPUTATIONS OF A AND K WHEN LINKING. -------------------------------------------------------------- ############################################################### CONDUCTING LINKING/DIF ITERATION: 1 ############################################################### ** COMPUTING TRANSFORMATION COEFFICIENTS, A and K ** Initial values for linking constants: A = .9578 K= -.7678 Minimization Function at initial A and K: 17.176490 Details regarding the minimization: Number of Iterations performed: 2 Function value at minimum: .219819 -------------------------------------------------------------- ** RESULTING METRIC TRANSFORMATION COEFFICIENTS ** ** A= .938371 ** K= -.795496 ** Summary statistics for TRANSFORMED ITEM PARAMETERS ** MEAN C= .088 VARIANCE C= .003 STD DEV C= .051 ******************************************************************************* ROUTINE "PAIRDIF3" CONDUCTS A PAIRWISE (2-GROUP) DIF ANALYSIS for 3-PL model. It was written by Stephen Stark at UIUC and last revised on 05/25/00. ******************************************************************************* --------------------------------------------------------------- Linking Constants used in DIF analysis: A = .9384 K= -.7955 Number of Items for DIF analysis: 32 Degrees of freedom: 3 Critical Chi-Square (uncorrected: P <.05)= 7.8147 Critical Chi-Square (corrected)= 15.3202 Critical P-value (uncorrected: P <. 05)= .05000000 Critical P-value (corrected)= .00156250 --------------------------------------------------------------- ITEM P obs. DIF PRESENT using P<.05 Corrected P --------------------------------------------------------------- 1 .03910006 YES NO 2 .22354231 NO NO 3 .55714918 NO NO 4 .00030662 YES YES 5 .00669607 YES NO 6 .47102172 NO NO 7 .00001849 YES YES 8 .00527094 YES NO 9 .12618701 NO NO 10 .02565616 YES NO 11 .46091057 NO NO 12 .05661002 NO NO 13 .00001317 YES YES 14 .74325914 NO NO 15 .70399638 NO NO 16 .00314141 YES NO 17 .12334338 NO NO 18 .33370542 NO NO 19 .13698496 NO NO 20 .22581136 NO NO 21 .36562514 NO NO 22 .10503999 NO NO 23 .58623106 NO NO 24 .21399115 NO NO 25 .02355756 YES NO 26 .51280795 NO NO 27 .51541161 NO NO 28 .00079191 YES YES 29 .65164401 NO NO 30 .89292899 NO NO 31 .04190196 YES NO 32 .28610441 NO NO ############################################################### CONDUCTING LINKING/DIF ITERATION: 2 ############################################################### ** COMPUTING TRANSFORMATION COEFFICIENTS, A and K ** Initial values for linking constants: A = .9623 K= -.6306 Minimization Function at initial A and K: 27.900160 Details regarding the minimization: Number of Iterations performed: 51 Function value at minimum: .053991 -------------------------------------------------------------- ** RESULTING METRIC TRANSFORMATION COEFFICIENTS ** ** A= 1.012231 ** K= -.885046 ** Summary statistics for TRANSFORMED ITEM PARAMETERS ** MEAN C= .088 VARIANCE C= .003 STD DEV C= .051 ******************************************************************************* ROUTINE "PAIRDIF3" CONDUCTS A PAIRWISE (2-GROUP) DIF ANALYSIS for 3-PL model. It was written by Stephen Stark at UIUC and last revised on 05/25/00. ******************************************************************************* --------------------------------------------------------------- Linking Constants used in DIF analysis: A = 1.0122 K= -.8850 Number of Items for DIF analysis: 32 Degrees of freedom: 3 Critical Chi-Square (uncorrected: P <.05)= 7.8147 Critical Chi-Square (corrected)= 15.3202 Critical P-value (uncorrected: P <. 05)= .05000000 Critical P-value (corrected)= .00156250 --------------------------------------------------------------- ITEM P obs. DIF PRESENT using P<.05 Corrected P --------------------------------------------------------------- 1 .06734106 NO NO 2 .05817988 NO NO 3 .45125276 NO NO 4 .00193015 YES NO 5 .00646807 YES NO 6 .49390288 NO NO 7 .00004759 YES YES 8 .00612821 YES NO 9 .14695634 NO NO 10 .05810135 NO NO 11 .66202811 NO NO 12 .01235684 YES NO 13 .00004415 YES YES 14 .38005657 NO NO 15 .82641154 NO NO 16 .02898943 YES NO 17 .07663860 NO NO 18 .41430692 NO NO 19 .13271824 NO NO 20 .29229357 NO NO 21 .34594173 NO NO 22 .08438462 NO NO 23 .63231742 NO NO 24 .27296518 NO NO 25 .02307260 YES NO 26 .63951175 NO NO 27 .71462203 NO NO 28 .00113008 YES YES 29 .73799300 NO NO 30 .94548167 NO NO 31 .05641018 NO NO 32 .40999494 NO NO NOW COMPARE ITEM IDS ON CONSECUTIVE ITERATIONS: 1 = USE to link (no dif); 0 = DO NOT USE (dif) LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=0 ABSDIFF=1 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 SUM OF ABSOLUTE DIFFERENCES BETWEEN DIF VALUES = 1 ############################################################### CONDUCTING LINKING/DIF ITERATION: 3 ############################################################### ** COMPUTING TRANSFORMATION COEFFICIENTS, A and K ** Initial values for linking constants: A = .9619 K= -.6632 Minimization Function at initial A and K: 26.535260 Details regarding the minimization: Number of Iterations performed: 51 Function value at minimum: .064095 -------------------------------------------------------------- ** RESULTING METRIC TRANSFORMATION COEFFICIENTS ** ** A= 1.018418 ** K= -.909612 ** Summary statistics for TRANSFORMED ITEM PARAMETERS ** MEAN C= .088 VARIANCE C= .003 STD DEV C= .051 ******************************************************************************* ROUTINE "PAIRDIF3" CONDUCTS A PAIRWISE (2-GROUP) DIF ANALYSIS for 3-PL model. It was written by Stephen Stark at UIUC and last revised on 05/25/00. ******************************************************************************* --------------------------------------------------------------- Linking Constants used in DIF analysis: A = 1.0184 K= -.9096 Number of Items for DIF analysis: 32 Degrees of freedom: 3 Critical Chi-Square (uncorrected: P <.05)= 7.8147 Critical Chi-Square (corrected)= 15.3202 Critical P-value (uncorrected: P <. 05)= .05000000 Critical P-value (corrected)= .00156250 --------------------------------------------------------------- ITEM P obs. DIF PRESENT using P<.05 Corrected P --------------------------------------------------------------- 1 .09412338 NO NO 2 .04301331 YES NO 3 .32949457 NO NO 4 .00384791 YES NO 5 .00299189 YES NO 6 .41409214 NO NO 7 .00012955 YES YES 8 .00402307 YES NO 9 .10476921 NO NO 10 .07945808 NO NO 11 .63537342 NO NO 12 .00513459 YES NO 13 .00012454 YES YES 14 .28868180 NO NO 15 .79046522 NO NO 16 .05051071 NO NO 17 .04265126 YES NO 18 .35307695 NO NO 19 .16419812 NO NO 20 .24916698 NO NO 21 .31630864 NO NO 22 .10641592 NO NO 23 .60329573 NO NO 24 .23438787 NO NO 25 .03020900 YES NO 26 .54493682 NO NO 27 .70855205 NO NO 28 .00196856 YES NO 29 .73183704 NO NO 30 .91947751 NO NO 31 .08203290 NO NO 32 .34136873 NO NO NOW COMPARE ITEM IDS ON CONSECUTIVE ITERATIONS: 1 = USE to link (no dif); 0 = DO NOT USE (dif) LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=0 ABSDIFF=1 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 SUM OF ABSOLUTE DIFFERENCES BETWEEN DIF VALUES = 1 ############################################################### CONDUCTING LINKING/DIF ITERATION: 4 ############################################################### ** COMPUTING TRANSFORMATION COEFFICIENTS, A and K ** Initial values for linking constants: A = .9567 K= -.6971 Minimization Function at initial A and K: 22.753460 Details regarding the minimization: Number of Iterations performed: 49 Function value at minimum: .063773 -------------------------------------------------------------- ** RESULTING METRIC TRANSFORMATION COEFFICIENTS ** ** A= 1.010838 ** K= -.918427 ** Summary statistics for TRANSFORMED ITEM PARAMETERS ** MEAN C= .088 VARIANCE C= .003 STD DEV C= .051 ******************************************************************************* ROUTINE "PAIRDIF3" CONDUCTS A PAIRWISE (2-GROUP) DIF ANALYSIS for 3-PL model. It was written by Stephen Stark at UIUC and last revised on 05/25/00. ******************************************************************************* --------------------------------------------------------------- Linking Constants used in DIF analysis: A = 1.0108 K= -.9184 Number of Items for DIF analysis: 32 Degrees of freedom: 3 Critical Chi-Square (uncorrected: P <.05)= 7.8147 Critical Chi-Square (corrected)= 15.3202 Critical P-value (uncorrected: P <. 05)= .05000000 Critical P-value (corrected)= .00156250 --------------------------------------------------------------- ITEM P obs. DIF PRESENT using P<.05 Corrected P --------------------------------------------------------------- 1 .12047898 NO NO 2 .04130962 YES NO 3 .23741775 NO NO 4 .00584714 YES NO 5 .00126560 YES YES 6 .34285648 NO NO 7 .00030962 YES YES 8 .00248643 YES NO 9 .06964681 NO NO 10 .09610029 NO NO 11 .56544545 NO NO 12 .00270206 YES NO 13 .00029028 YES YES 14 .25384304 NO NO 15 .72743724 NO NO 16 .06346142 NO NO 17 .02502750 YES NO 18 .28382106 NO NO 19 .20504999 NO NO 20 .19756818 NO NO 21 .29034072 NO NO 22 .13833491 NO NO 23 .56586089 NO NO 24 .18948623 NO NO 25 .04055681 YES NO 26 .43148553 NO NO 27 .66722624 NO NO 28 .00331700 YES NO 29 .70951157 NO NO 30 .87887409 NO NO 31 .11321390 NO NO 32 .25906359 NO NO NOW COMPARE ITEM IDS ON CONSECUTIVE ITERATIONS: 1 = USE to link (no dif); 0 = DO NOT USE (dif) LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=1 ABSDIFF=1 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 SUM OF ABSOLUTE DIFFERENCES BETWEEN DIF VALUES = 1 ############################################################### CONDUCTING LINKING/DIF ITERATION: 5 ############################################################### ** COMPUTING TRANSFORMATION COEFFICIENTS, A and K ** Initial values for linking constants: A = .9574 K= -.6816 Minimization Function at initial A and K: 26.126230 Details regarding the minimization: Number of Iterations performed: 51 Function value at minimum: .049961 -------------------------------------------------------------- ** RESULTING METRIC TRANSFORMATION COEFFICIENTS ** ** A= 1.011183 ** K= -.928720 ** Summary statistics for TRANSFORMED ITEM PARAMETERS ** MEAN C= .088 VARIANCE C= .003 STD DEV C= .051 ******************************************************************************* ROUTINE "PAIRDIF3" CONDUCTS A PAIRWISE (2-GROUP) DIF ANALYSIS for 3-PL model. It was written by Stephen Stark at UIUC and last revised on 05/25/00. ******************************************************************************* --------------------------------------------------------------- Linking Constants used in DIF analysis: A = 1.0112 K= -.9287 Number of Items for DIF analysis: 32 Degrees of freedom: 3 Critical Chi-Square (uncorrected: P <.05)= 7.8147 Critical Chi-Square (corrected)= 15.3202 Critical P-value (uncorrected: P <. 05)= .05000000 Critical P-value (corrected)= .00156250 --------------------------------------------------------------- ITEM P obs. DIF PRESENT using P<.05 Corrected P --------------------------------------------------------------- 1 .14041915 NO NO 2 .03635995 YES NO 3 .18954883 NO NO 4 .00792875 YES NO 5 .00076273 YES YES 6 .30227515 NO NO 7 .00050929 YES YES 8 .00188710 YES NO 9 .05427834 NO NO 10 .10958683 NO NO 11 .53609314 NO NO 12 .00165675 YES NO 13 .00047828 YES YES 14 .22077131 NO NO 15 .69637378 NO NO 16 .07882727 NO NO 17 .01735503 YES NO 18 .25190427 NO NO 19 .22920841 NO NO 20 .17381128 NO NO 21 .27381409 NO NO 22 .15696593 NO NO 23 .54512842 NO NO 24 .16941837 NO NO 25 .04698785 YES NO 26 .37742571 NO NO 27 .65063530 NO NO 28 .00442134 YES NO 29 .70186266 NO NO 30 .85418315 NO NO 31 .13523653 NO NO 32 .22381189 NO NO NOW COMPARE ITEM IDS ON CONSECUTIVE ITERATIONS: 1 = USE to link (no dif); 0 = DO NOT USE (dif) LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=0 LINK1(I)=0 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 LINK2(I)=1 LINK1(I)=1 ABSDIFF=0 SUM OF ABSOLUTE DIFFERENCES BETWEEN DIF VALUES = 0 The SAME ITEMS were identified as having DIF on CONSECUTIVE ITERATIONS. The linking and DIF analysis is done. ##################################################### BELOW IS A SUMMARY OF THE RESULTS: "YES" INDICATES THAT DIF IS PRESENT ITEM 1 : NO ITEM 2 : NO ITEM 3 : NO ITEM 4 : NO ITEM 5 : YES ITEM 6 : NO ITEM 7 : YES ITEM 8 : NO ITEM 9 : NO ITEM 10 : NO ITEM 11 : NO ITEM 12 : NO ITEM 13 : YES ITEM 14 : NO ITEM 15 : NO ITEM 16 : NO ITEM 17 : NO ITEM 18 : NO ITEM 19 : NO ITEM 20 : NO ITEM 21 : NO ITEM 22 : NO ITEM 23 : NO ITEM 24 : NO ITEM 25 : NO ITEM 26 : NO ITEM 27 : NO ITEM 28 : NO ITEM 29 : NO ITEM 30 : NO ITEM 31 : NO ITEM 32 : NO