[��鼼��] ��Ŀ��Ӧ��е�a �ֲ�ѡ��Ӧ��

ѡ��Ǽ��Ӧ��һ��ǳ��Ҫ�Ļ��ڡ�Ŀǰ��Ӧ��鳣�õ�ѡ��Ҫ��Ϣ��ѡ�ⷨ�ͼ�Ȩ��ģ�͡��ַ��ŵ��ڿ��ݱ��Ե��Ӧ��þ��Ϣ��Ŀ��ԣ�Ȼ��ʵ��з��ִ��ڷǳ��Եľ��ԡ��Ҫ��¼��棺
��1��ͳ��ѡ��ڲ��İ�ȫ�Է��ֳ�һ��ľ��ԡ��ͳ��ѡ��ǰ��Ŀ��Ϣ��ѡ��Ŀ�Ĳ��ʹ�ø��ֶȵ��Ŀ��ع��ʹ��ߣ��İ�ȫ�Գ�Ϊһ��⡣
��2��ͳ��ѡ��Խ��˲��Ч�ʡ��ͳ��ѡ��ڽ��鰲ȫ��ʱ�� Sympson-Hetter ��FSH ��ܹ�ʹ�ø��ֶ��Ŀ��ع��ʱ��һ��ֵ֮�䣬��ǵ��Ŀ��ֶ��ʱ��Ч��ߣ��⵼��˲��Ч�ʵĽ��͡�
��3��ͳ��ѡ��ľ޴��˷ѡ��ͳ��Ŀѡ��ʹ�ø��ֶȵ��Ŀ��ع⣬�е��ֶȵ��Ŀû�б��Ӧ�á��Щû�б��Ӧ�õ��Ŀ��Ӧ��һ��ض��ʱ��ͨ��һ��ľ޴��˷ѡ�
��4��ͳ��ѡ��Ŀ��䷽��ⲹ��ĳɱ��ߡ��ⲹ�䷽��о��Ҫ��ڡ��Ѳ��䡱�͡��䡱��ַ�ʽ�ϡ��Ѳ��䡱��ָ��Ŀ�뱻��̭��Ŀ��ͬ��ѧ��磬��ͬ��Ѷȡ��ֶȵȡ��䡱��ָ��һ��Ƶġ��ѡ�񲹳��Ŀ��ʱ��ٶԱ��̭��Ŀ��Ŀ��Ѷȡ��ֶȵ�ƥ�䡣Chang �� Ying ��˵��о��ڴ�ͳ��ѡ��˵��á��Ѳ��䡱��Ҫ��㹻��ĸ��ֶ��Ŀ��ڹ��ع��ʱ��õ��Ŀ��˳ɱ��ߡ��á��䡱��ʽ��ʱ�򣬴�ͳ��ѡ��ԣ�ʹ�þ��ṹ�⵽��ƻ��
��Դ�ͳ��Ŀѡ��⣬��ǵ��Ϣ��ѡ�ⷨ�ᵼ��ĳЩ��ع��ʸߣ��ع�Ȳ��ȣ�Chang �� Ying ��һ�ְ� a �ֲ�ķ��ⰴ��ֶȵĴ�С�ֲ㣬ѡ��ֶ��С��ع��ʡ��ֶȴ��ֻ��Ѷȸ��С��ṩ��Ϣ��ھ��Ѷ�ֵ��Զ�ĵط��Ϣ��󣬶��ֶ�С��Ȼ�ṩ��Ϣ��СһЩ��ڽϿ��ڶ��ṩһ��Ϣ�� CAT ��տ�ʼʱ��Ĺ��Ƚϴ�ģ��Դ�ʱѡ��ֶȴ��Ⲣû�кܴ�İ��ֻ��ڿ��ƱȽ�׼ȷʱ��Щ��ֶȴ��Ž�Ϊ��Ч��Щ��ǣ��˰� a �ֲ��CAT ѡ�ⷽ��
a �ֲ�ѡ��ԶԾ��ڴ�ͳѡ��Ӧ�õļ��衪��ѡ��ֶ��Ŀ��ʱ�򣬲��Ч��󡪡��ս�� Fisher ��Ϣ��ֵδ֪�Ļ��ø��ֶ��Ŀ��һ��ܹ��֤��Ч�ʵĻ�á��֮��һ�£��ڼ��Ӧ�Բ��ڽ׶Σ��ڶԱ��ֵ�Ĳ��ȷ��֭��ڼ��Ӧ�Բ��ڽ׶ι�� Fisher ��Ŀ��Ϣ��ѡ��ֶȵ��Ŀ�ǲ��˵ġ��׶ηֲ�ѡ��ŵ��ܹ�ʹ��һЩ��ֶ��Ŀ��ع��ӣ�ʹ��Ŀ֮��Ӧ�ø��ƽ�⡣��Ҫ�ǰ��Ŀ��ֶȵĸߵͷֲ㣬Ȼ��ÿһ��ж��ݱ��ķ�Ӧѡ��Ӧ�ѶȺ��ֶȵ��Ŀ��
�� a �ֲ�ѡ�ⷨ�Ļ��˼��ǣ��ȣ��ⰴ��ֶ� a ��С��˳��У��ɸ��Ŀ(x)�ֳ��ɸ��(y)��ÿ�� n = [x/y]��Ŀ��Ȼ��ֱ�� y ��ѡȡ a ֵ��С��Ŀ��ɵ� 1 ��(y ��Ŀ)��С��ɵ� 2��⣬��ƣ� ��a ֵ�� x-(y-l)n ��Ŀ��ɵ� n ��⡣��е� 1��е��ֶ��С�� n ��е��󡣽��鰴��鳤��ͬ��ֳ� n ��֣��е�� k ��ʱ��ĵ� k ��ѡ��Ѷ��ѹ��ӽ��ʩ�⡣�ڲ��ĳ��׶� a ��С��Ŀ��ã��ڲ��ĺ�׶� a ��Ŀ��á��ѡ��ֶȶ��С��Խ��ѡ��ֶ�Խ��䲽��£�
1) ��ֶȽ��ֳ�k�㣻
2) ��ֳ� ��׶Σ�
3) ��ĵ�k��׶ΰ��nk��Ŀ�� Ŀ��ͨ��"b ƥ�䷨"��ݿ��ǰ��ֵ��ѡȡ�Ѷ��ӽ��⣩��ĵ� ��ѡȡ��ע��nnnk ... 12Ӧ��ڲ��鳤�ȡ�
4) ��k 1,2,...,k�ظ��Chang �� Ying��˰�a�ֲ㷽��봫ͳ��ѡ��ԡ��a�ֲ㷽��(descendinga-stratified method��D��STR)�ͷ�ϵͳ�Եķֲ㷽��(non-system a-stratified method��N��STR)��ѡ��Ч��˱Ƚ��о��н�� a �ֲ㷽�� a �ֲ㷽��֮ͬ��ڸ��Ŀ��ֶȲ��ֲ�󣬽�� a �ֲ㷽��У�ǰ��Ĳ��а��Ÿ��ֶ��Ŀ��Ĳ��а��ŵ��ֶ��Ŀ��ڲ��ڽ׶�ʵʩ��ֶȵ��Ŀ��ĺ��ڽ׶�ʵʩ��ֶȵ��Ŀ��ϵͳ�ķֲ�ѡ��ԣ��Ҫ��ڷֲ��У��һ��е��ֶȵ��Ŀ��ĺ�С��ֶ��Ŀ�ں��漸�㣬��ڽ׶��ʵʩ�е��ֶȵ��Ŀ��Ѹ��ֶȺ͵��ֶȵ��Ŀ��ڲ��ڽ׶Ρ�Chang �� Ying��˵��о��û�н��Ͳ��Ч�ʵ�ǰ��£��봫ͳ��ѡ��ȣ�a �ֲ㷽��ܹ�ƽ�ⲻͬ��ֶ��Ŀ��Ӧ�ã��ӵ��ֶ��Ŀ��ع�ȡ�� Chang �� Ying �Ȼ��Ŀ��ַ��ϵıȽϡ��о�� FSH��ԭ��ȣ��Լ�� 18��Ŀ��滻��б��̭��Ŀ��Ҫ�Ǹ��ֶ��Ŀ��ˣ��Ҫ��ͬ��ֶȵ��Ŀ��䣬��ŶԸ��౻�Խ��в��飬��Ľṹ��Ҫ��ر��ƻ�� a �ֲ㷽��ֻ��Ҫ��С��滻(�� 3��)��Щ��Ŀ��ֲ��ڸ��У��ʣ�µ��Ҳ�ǱȽ��ģ��Ŀ��Ӧ�÷ֲ��Ӿ��ȣ�ͨ��飬��ṹҲ�ܹ��ȶ��û�н��Ͳ��Ч�ʣ��Ÿ��ı��ԲμӲ��飬a �ֲ㷽��ṹ��Է�� FSH ��ռ��ơ��ʽ��ʱ�򣬲�� a �ֲ㷽��Ᵽ��һ��Ľṹ��ͬ��ĺʹ��̬�ֲ��Ŀ��̭��Ŀ�Ǿ��ȵطֲ��ڸ��еġ��֮��ȣ�� FSH ��Ľṹ��ƻ��ˣ��һ��Ҫ��ֶȵ��Ŀ��ɵ��⵽�ƻ��⡣�� FSH ��У��滻��Ŀ�ı��ԶԶ�� a �ֲ㷽��б��滻��Ŀ�ı��Chang �� Ying��˵��о�� a �ֲ㷽��D��STR �� N��STR ��У��ڸ��ֶȺ͵��ֶ��Ŀ��ƽ��Ӧ�÷��һ�µġ�� a �ֲ㷽��Ƶ�ƽ��ƫ��;��С��N��STR ��ƽ��ƫ��֮��D��STR ��ƽ��ƫ��˵��ڲ��ڽ׶�ѡ��ֶ��Ŀ�� a �ֲ㷽��Ա��ȷ��Ϊ��Chang �� Ying�Ĺ۵㣬��Ƶ��ʵ��ϴ�ʱ��ڼ��Ӧ��Ŀ�ʼ�׶β��ֶȽ�С��Ŀ�ܹ��ֶȸߵ��Ŀ��ṩ��Ϣ��ڲ��׶��ڱ��Ե��Ƴ�ֵ��Զ��ֵ��ô��ʹʩ�� a ֵ��С��Ѷ��ֵ�൱��Ŀ��Ҳ��ṩһ��Ϣ��ˮƽֵ��дֹ�� ʱʹ�� a ֵ��Ŀʵ��˷ѡ��ڲ��ĺ�׶Σ��ֵ��ֵԽ��Խ�ӽ�ʱ�� a ֵ��Ŀ��ڱ��Ե��ơ�� CAT ��̵��У��ص��ֶȴ��Ŀ��ֶ�С��Ŀ��ٱ��á��ˣ��Ĺ��У�a �ֲ㷽��ܹ��ڲ��ƻ��Ч�ʵ��ʹ��Ŀ��Ӧ�ø��ƽ�⡣��ڿ��Ǵ�һ��̶��ѡ��Ŀ��ʱ��a �ֲ㷽��ҲҪ�� D��STR ��Ч��Ŀ�ص��ʡ��Ŀ�ع��ʵķֲ��ȷ��棬�о�� a �ֲ㷽��ڱ�֤��Ͳ��Ч�ʵ�ǰ��3 �ֲַ�ѡ��ԵıȽϱ�� a �ֲ㷽��һ�ֱȽϺõ�ѡ��ԡ�ͬʱ��о��a �ֲ㷽��봫ͳ��ѡ��ȣ��پ�� 4 ��Ǳ��ƣ�
(1) �봫ͳ��Ϣ��ȣ��ܹ��ṩһ��Ч�ʡ��ڲ��ڽ׶Σ�ֻ�е��Ŀ��Ӧ��ѶȲ�� b �뱻�Ե��㹻�ӽ��ʱ�򣬸��ֶȵ��Ŀ��õġ��ˣ��ڲ��Ŀ�ʼ�׶��ֶȵ͵��Ŀ��ڲ��ʱ��ֶȸߵ��ĿҲ��ܹ��ٱ��봫ͳ��ѡ��Խӽ��Ƶ�Ч�ʡ�
(2) �� FSH ��ȣ�a �ֲ㷽��ʵʩ��FSH ��ڲ��ڽ׶θ��ֶ��Ŀ�Ĺ��Ӧ�ã��Ų��̣��ת�Ƶ��ֶȵ��Ŀ��ʹ��Ŀ�ع�Ȳ�ƽ�⡣��ͳ��ѡ��Բ�� Symopson-Hetter ��Ŀ��ع�ȣ��ʲôʱ��ӻ��̭��һ��Ŀ��Ŀ�ع��ģ��Ҫ��½��С��ع�Ȳ��ļ��Ҫ��ʱ�䲢��Ҫһ̨��ĸ��ٳ��ͼ�� a �ֲ㷽��Ҫ��Ŀ�ع��Ʋ��ļ��㣬��Ŀ�滻��ʱ��Ҳ��Ҫ��ļ��㣬ʹ��Ĺ��Ҳ��ü��С�
(3) a �ֲ㷽��ȴ�ͳ��Ŀѡ��ܹ��õ�ƽ��Ŀ�ع�ȣ��͸��ֶ��Ŀ��ع��ʣ��е��ֶȺ͵��ֶ��Ŀ��ع��ʡ�a �ֲ㷽��ǴӸߡ��к͵��ֶȲ��а��ձ��ѡ��ȵ��Ŀ��ع��ʵķֲ��ͱ�ø��ȡ��Ŀ��Ӧ�ã��̭��Ŀ�Ĳ��Ľ��ɱ��϶��бȽ��Ե��ơ�
(4) a �ֲ㷽��ʹ�ø�Ч�ļ��Ӧ�Բ��ʵ�֡�a �ֲ㷽��ܹ��͸��ֶ��Ŀ��ع��ʣ��ܹ��ӵ��ֶ��Ŀ��ع��ʡ��ˣ��Զ��ʹ�ø��ֶȺ͵��ֶ��Ŀ��ع��ȣ��ʹ��Ĺ��Ϊ��ܡ�a �ֲ㷽��Ҳ��ʹ�ò��Ŀ��ԭ��е��Ŀ��ѧ�� FSH ��Ҫ��Ŀ��и��ֶȣ��ǱȽ��ѵģ�ͬʱ��ά��ĳɱ��
�ֲ�ѡ��Ŀǰ��Բ��ѧ�磬�ر��Ǽ��Ӧ��е�ѡ��о��չ��һ��Ҫ��ƣ�Ӧ��˵��ĳ��ϣ��Ѿ��Ϊ��Ӧ��ѡ��о��һ��Ҫ��