反馈规则：

相机抉择

在采用反馈规则时，制定经济政策的方法称为相机抉择。相机抉择是指政府在运用宏观经济政策来调节经济时，可以根据市场情况和各项调节措施的特点，机动地决定和选择当前究竟应采取哪一种或哪几种政策措施。

This paper provides a system using feedback rule-based learning method of automatic indexing(FRBLAI )for medical literature.The system has a relatively high performance in subject indexing problem,which involves the procedure of combination of Medical Headings and subheadings.Furthermore,FRBLAI avoids the main obstacle of word segmentation in Chinese information processing.Also the paper has a detailed description of the architecture of the indexing system.And finally,it gives an automatic indexing experiment in medical literature,which shows FRBLAI is a promising system for automatic indexing