Biostatistics and Experimental Design 2003 9 12 l

生物统计 与 试验设计 Biostatistics and Experimental Design 畜牧专业 2003. 9 ～ 12

主要参考书 l 《生物统计学》，杜荣骞，1999，高等教育出 版社 l 《应用概率统计》，曾善玉主编，2000，科学 出版社 l 《Statistical Methods》，G. W. Snedecor and W. G. Cocheran，7 th edition，1980，The Iowa State University Press，USA. l 课堂讲义下载地址：ftp: //10. 2. 21. 130

统计学的用途 Description Design l Provide a data l Assist in the summary design of experiments and l Help discover field studies trends and l A priori decisions patterns. about usefulness l Evaluate of experiments. magnitude and direction of experimental effects Hypothesis-testing l Evaluate biological hypotheses by testing to see whether observed patterns are “real” or simply due to chance.

What statistics can and can’t do Can l provide objective criteria for evaluating hypotheses l help optimize effort l help you critically evaluate arguments Can’t l tell the truth (probabilistic conclusions only!) l compensate for poor design l indicate biological significance: statistical significance does not mean biological significance, nor vice versa!

Some opinions of statistics “If your experiment needs statistics, you should have done a better experiment. ” Ernest Rutherford “To call in a statistician after the experiment is done may be no more than asking him to perform a postmortem examination; he may be able to say what the experiment died of. ” Sir Ronald Fisher

Some opinions of statistics “There are three types of lies: lies, damn lies, and statistics!” Be njamin Disraeli “A knowledge of statistics is like a knowledge of foreign languages or of algebra; it may prove of use at any time under any circumstances. ” A. L. Bowley