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标题: [求助]explain it to me ?? [打印本页]

作者: aiyinsitan 时间: 2004-4-1 19:46
标题: [求助]explain it to me ??

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Stat > Basic Statistics > 2 Variances

Stat > ANOVA > Test for Equal Variances

我的问题是,这两种方法都是检验两个样本的方差是否相等,或者说是方差的置信区间的范围的操作,它们有什么不同吗?/分别用在什么场合下呢??

作者: Link 时间: 2004-4-2 16:59
Stat > Basic Statistics > 2 Variances

You can use the variance test to perform hypothesis tests for equality, or homogeneity, of variance among two populations using an F-test and Levene’s test. Many statistical procedures, including the two sample t-procedures, assume that the two samples are from populations with equal variance. The variance test procedure will test the validity of this assumption.

Stat > ANOVA > Test for Equal Variances

Use variance test to perform hypothesis tests for equality or homogeneity of variance using Bartlett’s and Levene’s tests. An F Test replaces Bartlett’s test when you have just two levels.

Many statistical procedures, including analysis of variance, assume that although different samples may come from populations with different means, they have the same variance. The effect of unequal variances upon inferences depends in part upon whether your model includes fixed or random effects, disparities in sample sizes, and the choice of multiple comparison procedure. The ANOVA F-test is only slightly affected by inequality of variance if the model contains fixed factors only and has equal or nearly equal sample sizes. F-tests involving random effects may be substantially affected, however [18]. Use the variance test procedure to test the validity of the equal variance assumption.

作者: aiyinsitan 时间: 2004-4-2 21:37
谢谢回复，但是我就是因为看不懂英文的意思，所以才问的呀，可以用汉语解释吗？？

作者: aiyinsitan 时间: 2004-4-4 17:58
还是没有答案吗？？

作者: aiyinsitan 时间: 2004-4-6 20:47
答案呀，HELP！！

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