码迷,mamicode.com
首页 > 其他好文 > 详细

t检验,T Test (Student’s T-Test)

时间:2018-12-31 11:24:30      阅读:2083      评论:0      收藏:0      [点我收藏+]

标签:out   cer   ace   may   control   different   example   数据   his   

1、什么是T test?

t-test:比较数据的均值,告诉你这两者之间是否相同,并给出这种不同的显著性(即是否是因为偶然导致的不同)

The t test (also called Student’s T Test) compares two averages (means) and tells you if they are 
different from each other. The t test also tells you how significant the differences are; In other words it lets you know if those differences could have happened by chance.

 例子:制药公司可能想测试一种新的抗癌药物,看看它是否能提高预期寿命。在实验中,总有一个对照组(给一组人服用安慰剂,或“糖丸”)。对照组的平均预期寿命为+5岁,而服用新药的组的平均预期寿命为+6岁。看来这种药可能有效。但这可能是一个巧合。为了验证这一点,研究人员将使用Student’s t-test来发现结果是否可以在整个人群中重复

Student’s T-tests can be used in real life to compare means. For example, a drug company may 
want to test a new cancer drug to find out if it improves life expectancy. In an experiment, 
there’s always a control group (a group who are given a placebo, or “sugar pill”). The control
 group may show an average life expectancy of +5 years, while the group taking the new drug 
might have a life expectancy of +6 years. It would seem that the drug might work. But it could 
be due to a fluke. To test this, researchers would use a Student’s t-test to find out if the 
results are repeatable for an entire population.

 2、The T Score.

T Score:是两组之间的差异与组内差异的比值。t值越大,组间差异越大。t值越小,组间的相似性越大。t得分为3表示两个组之间的差异是它们内部差异的三倍。当您运行t测试时,t值越大,结果越有可能是可重复的

The t score is a ratio between the difference between two groups and the difference within the
 groups. The larger the t score, the more difference there is between groups. The smaller the t
 score, the more similarity there is between groups. A t score of 3 means that the groups are 
three times as different from each other as they are within each other. When you run a t test, 
the bigger the t-value, the more likely it is that the results are repeatable

 

t检验,T Test (Student’s T-Test)

标签:out   cer   ace   may   control   different   example   数据   his   

原文地址:https://www.cnblogs.com/djx571/p/10201538.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!