TITLE: differentiation on item level
DATA:	 FILE IS subtest_item_scores.dat;
VARIABLE:	 NAMES ARE x1-x15 age age2;
MISSING ARE ALL(-999);
		 CATEGORICAL ARE x1-x15;
ANALYSIS:	 TYPE = RANDOM;
		 ALGORITHM=INTEGRATION;
MODEL: 
 g BY x1-x15*  (l1-l15);
g@1;
g2|g xwith g;
gAge|g xwith age;
gAge2|g xwith age2;
g on age;
g on age2;
x1 on g2 (q1);
x2 on g2 (q2);
x3 on g2 (q3);
x4 on g2 (q4);
x5 on g2 (q5);
x6 on g2 (q6);
x7 on g2 (q7);
x8 on g2 (q8);
x9 on g2 (q9);
x10 on g2 (q10);
x11 on g2 (q11);
x12 on g2 (q12);
x13 on g2 (q13);
x14 on g2 (q14);
x15 on g2 (q15);


x1 on gAge (r1);
x2 on gAge (r2);
x3 on gAge (r3);
x4 on gAge (r4);
x5 on gAge (r5);
x6 on gAge (r6);
x7 on gAge (r7);
x8 on gAge (r8);
x9 on gAge (r9);
x10 on gAge (r10);
x11 on gAge (r11);
x12 on gAge (r12);
x13 on gAge (r13);
x14 on gAge (r14);
x15 on gAge (r15);


x1 on gAge2 (s1);
x2 on gAge2 (s2);
x3 on gAge2 (s3);
x4 on gAge2 (s4);
x5 on gAge2 (s5);
x6 on gAge2 (s6);
x7 on gAge2 (s7);
x8 on gAge2 (s8);
x9 on gAge2 (s9);
x10 on gAge2 (s10);
x11 on gAge2 (s11);
x12 on gAge2 (s12);
x13 on gAge2 (s13);
x14 on gAge2 (s14);
x15 on gAge2 (s15);


MODEL CONSTRAINT:
new(y1 y2 y3);

q1=y1*l1;
q2=y1*l2;
q3=y1*l3;
q4=y1*l4;
q5=y1*l5;
q6=y1*l6;
q7=y1*l7;
q8=y1*l8;
q9=y1*l9;
q10=y1*l10;
q11=y1*l11;
q12=y1*l12;
q13=y1*l13;
q14=y1*l14;
q15=y1*l15;


r1=y2*l1;
r2=y2*l2;
r3=y2*l3;
r4=y2*l4;
r5=y2*l5;
r6=y2*l6;
r7=y2*l7;
r8=y2*l8;
r9=y2*l9;
r10=y2*l10;
r11=y2*l11;
r12=y2*l12;
r13=y2*l13;
r14=y2*l14;
r15=y2*l15;


s1=y3*l1;
s2=y3*l2;
s3=y3*l3;
s4=y3*l4;
s5=y3*l5;
s6=y3*l6;
s7=y3*l7;
s8=y3*l8;
s9=y3*l9;
s10=y3*l10;
s11=y3*l11;
s12=y3*l12;
s13=y3*l13;
s14=y3*l14;
s15=y3*l15;