T test

Hi all,

I did a t test to compare whether there is any significant
difference between two treatments or not? The SPSS output says that
there is a difference between the two treatments.

But when i go for the 95% confidence interval for the two
treatments individually it was concluded that there is no significant
difference. Beacuse the two confidence intervals are overlapping.

How it works? Below that i have attached my SPSS outputs. anyone
please help me.

Group Statistics

Treatment N Mean Std. Deviation Std. Error Mean
A 5 -2.1642 1.13053 0.50559
B 5 -0.5384 0.96450 0.43134

the variance of the two treatments are tested by Levenes test and that
gives there is no significant difference between the variance of the
two treatments.

the t value =-2.446

p value=0.040

mean difference=-1.6258

standard error of difference=0.66458

.

Relevant Pages

  • T test
    ... The SPSS output says that ... there is a difference between the two treatments. ... gives there is no significant difference between the variance of the ...
    (sci.stat.consult)
  • Re: T test
    ... The SPSS output says that ... :there is a difference between the two treatments. ... The individual CI's may overlap andstill the difference is ... standard error of means as such a simple way. ...
    (sci.stat.consult)
  • Re: Doesnt a t-test work here?
    ... significant difference somewhere when in fact there are none at all is ... t-test would be okay. ... different treatments all being compared to a control treatment. ... I know you guys are all statistics people so you will probably hate me ...
    (sci.stat.edu)
  • Re: T test
    ... Deviation Std. ... the variance of the two treatments are tested by Levenes test and that gives there is no significant difference between the variance of the two treatments. ...
    (sci.stat.math)
  • Re: T test
    ... > there is a difference between the two treatments. ... Beacuse the two confidence intervals are ... > the variance of the two treatments are tested by ... Based on your Levene test, assuming that the variances are equal, the common standard deviation is estimated by ...
    (sci.stat.math)