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Power analysis and effect size test 中文不太了解怎么说。可以在收集数据前估算需要的样本大小，在分析之后检验有效样本大小。楼主在网上搜一下有很多这方面的资源。附上一个sample effect size估算的SAS程序。
title "computation of min sample size";
data one;
rmsea0=.05;
rmseaa=.08;
d=16;
alpha=.05;
powd=.8;
powa=0;
n=0;
do until (powa>powd);
n+100;
ncp0=(n-1)*d*rmsea0**2;
ncpa=(n-1)*d*rmseaa**2;
if rmsea0<rmseaa then do;
cval=cinv(1-alpha,d,ncp0);
powa=1-(probchi(cval,d,ncpa));
end;
if rmsea0>rmseaa then do;
cval=cinv(alpha,d,ncp0);
powa=probchi(cval,d,ncpa);
end;
end;
dir=-1;
newn=n;
intv=200;
powdiff=powa-powd;
do until (powdiff<.001);
intv=intv*.5;
newn+dir*intv;
ncp0=(newn-1)*d*rmsea0**2;
ncpa=(newn-1)*d*rmseaa**2;
if rmsea0<rmseaa then do;
cval=cinv(1-alpha,d,ncp0);
powa=1-(probchi(cval,d,ncpa));
end;
if rmsea0>rmseaa then do;
cval=cinv(alpha,d,ncp0);
powa=probchi(cval,d,ncpa);
end;
powdiff=abs(powa-powd);
if powa<powd then dir=1; else dir=-1;
minn=newn;
output;
end;
run;

proc print data=one;
var rmsea0 rmseaa powd alpha d minn powa;
run;