请问什么是t-test

2025-03-05 22:57:48
推荐回答(5个)
回答1:

T检验,亦称student t检验(Student's t test),主要用于样本含量较小(例如n < 30),总体标准差σ未知的正态分布。T检验是用t分布理论来推论差异发生的概率,从而比较两个平均数的差异是否显著。它与f检验、卡方检验并列。t检验是戈斯特为了观测酿酒质量而发明的,并于1908年在Biometrika上公布。


扩展资料:

选用的检验方法必须符合其适用条件(注意:t检验的前提:1.来自正态分布总体; 2.随机样本 ;3.均数比较时,要求两样本总体方差相等,即具有方差齐性) 。理论上,即使样本量很小时,也可以进行t检验。(如样本量为10,一些学者声称甚至更小的样本也行),只要每组中变量呈正态分布,两组方差不会明显不同。

如上所述,可以通过观察数据的分布或进行正态性检验估计数据的正态假设。方差齐性的假设可进行F检验,或进行更有效的Levene's检验。如果不满足这些条件,可以采用校正的t检验,或者换用非参数检验代替t检验进行两组间均值的比较。

参考资料来源:百度百科-正态分布

参考资料来源:百度百科-T检验

回答2:

以下是个人理解 可能有不准确的 而且我学的是英文的 可能表达的不是很好

就是统计用的一种专业公式
用来算两组数的差别大小
只要是一种叫做p-value的
就是说假如你测定一个实验的p-value是5%
也就是说你有95%的信心确定这个实验它是正确的

在正规的实验里 只有当p-value小于5%的时候这个实验才算是可以在报告中提及
数值越小代表实验数据越精确 可信度越高

还有一个是找的专业资料 个人是没看懂~ LZ参考
T检验,亦称student t检验(Student's t test),主要用于样本含量较小(例如n<30),总体标准差σ未知的正态分布资料。

T检验是用于小样本(样本容量小于30)的两个平均值差异程度的检验方法。它是用T分布理论来推断差异发生的概率,从而判定两个平均数的差异是否显著。

T检验是戈斯特为了观测酿酒质量而发明的。戈斯特在位于都柏林的健力士酿酒厂担任统计学家,基于Claude Guinness聘用从牛津大学和剑桥大学出来的最好的毕业生以将生物化学及统计学应用到健力士工业程序的创新政策。戈特特于1908年在Biometrika上公布T检验,但因其老板认为其为商业机密而被迫使用笔名(学生)。实际上,戈斯特的真实身份不只是其它统计学家不知道,连其老板也不知道。

T检验的适用条件:正态分布资料

T检验的步骤

1、建立虚无假设H0:μ1 = μ2,即先假定两个总体平均数之间没有显著差异;

2、计算统计量T值,对于不同类型的问题选用不同的统计量计算方法;

1)如果要评断一个总体中的小样本平均数与总体平均值之间的差异程度,其统计量T值的计算公式为:

2)如果要评断两组样本平均数之间的差异程度,其统计量T值的计算公式为:

3、根据自由度df=n-1,查T值表,找出规定的T理论值并进行比较。理论值差异的显著水平为0.01级或0.05级。不同自由度的显著水平理论值记为T(df)0.01和T(df)0.05 这个就是我说的那个p-value= =

4、比较计算得到的t值和理论T值,推断发生的概率,依据下表给出的T值与差异显著性关系表作出判断。

回答3:

TEST
abbr.
Thesaurus of Engineering and Scientific Terms 收录工程学和科学术语的词典
网络
测试; 检测; 测试条件

1
It is a commonplace fact that holidays are a major test of any relationship.
度假对任何恋爱关系都是重大考验,这是常识。

2
The program is designed to test a candidate 's physical and mental limits.
特训的目的是要测试候选人的体能和精神极限。

回答4:

你的解释有一定的误导作用,我原文书籍得到
The P-value is not the probability that H0 is true, nor is it an error
probability. This probability is calculated assuming that the null hypothesis is true.
To determine the P-value, we must first decide which values of the test statistic
are at least as contradictory to H0 as the value obtained from our sample
希望可以帮助到你

回答5:

级考,就是几级考试那种。

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