Compare means between groups

[Riya]

Hey SPSS Gurus,

I wish to know the difference between mean comparison and significance testing.

I understand the meaning of significance testing. It is used to compare mean between groups. To check significance , we see p value i.e . lowest level at which null hypothesis can be rejected.

My question is :
If somebody asks the reason to go for significance testing. Instead we can simply compute means of two groups and check whether there is any difference.

What i understand the reason behind this is :
Since the number of cases for groups can be different we cannot directly say that there is a significant difference between groups

Is my understanding correct ??

[Ryan]

You state that you understand significance testing but then you ask a question which suggests the contrary. I recommend that you review what you learned about **inferential** statistics again.

Ryan

On Apr 1, 2013, at 10:41 AM, Riya <[hidden email]> wrote:

> Hey SPSS Gurus,
>
> I wish to know the difference between mean comparison and significance
> testing.
>
> I understand the meaning of significance testing. It is used to compare mean
> between groups. To check significance , we see p value i.e . lowest level at
> which null hypothesis can be rejected.
>
> My question is :
> If somebody asks the reason to go for significance testing. Instead we can
> simply compute means of two groups and check whether there is any
> difference.
>
> What i understand the reason behind this is :
> Since the number of cases for groups can be different we cannot directly say
> that there is a significant difference between groups
>
> Is my understanding correct ??
>
>
>
> --
> View this message in context: http://spssx-discussion.1045642.n5.nabble.com/Compare-means-between-groups-tp5719215.html
> Sent from the SPSSX Discussion mailing list archive at Nabble.com.
>
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[E. Bernardo]

Riya,

If you want to know if two population means are different, then you dont need to do testing for significant difference.  Test for significant difference is applicable only for random samples (i.e., sample data were drawn at random from the populations of interest).

Eins

---

From: Riya <[hidden email]>
To: [hidden email]
Sent: Monday, April 1, 2013 10:41 PM
Subject: Compare means between groups

Hey SPSS Gurus,

I wish to know the difference between mean comparison and significance
testing.

I understand the meaning of significance testing. It is used to compare mean
between groups. To check significance , we see p value i.e . lowest level at
which null hypothesis can be rejected.

My question is :
If somebody asks the reason to go for significance testing. Instead we can
simply compute means of two groups and check whether there is any
difference.

What i understand the reason behind this is :
Since the number of cases for groups can be different we cannot directly say
that there is a significant difference between groups

Is my understanding correct ??



--
View this message in context: http://spssx-discussion.1045642.n5.nabble.com/Compare-means-between-groups-tp5719215.html
Sent from the SPSSX Discussion mailing list archive at Nabble.com.

=====================
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command. To leave the list, send the command
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[Riya]

Thank you very much for your response. In significance testing, i have read compare means of two populations. If this is applicable only for sample data i am wondering the hypothesis test for differences betweeen two population means.

Thanks in advance !

[Bruce Weaver]

Riya, the reason it is called inferential statistics is that one uses the means of two random samples to make an inference about the means of the two corresponding populations (most often, whether they are the same or not).  One (almost) never has the population means.  If one did have two population means, there would be no need for testing. Either they would be the same, or they would not.

It would appear that you need a good introductory textbook.  What discipline are you in?  List members may be able to recommend some books with examples relevant to your field.  Meanwhile, you could take a look at David Lane's Hyperstat textbook (Google will find it for you).

HTH.

Riya wrote

Thank you very much for your response. In significance testing, i have read compare means of two populations. If this is applicable only for sample data i am wondering the hypothesis test for differences betweeen two population means.

Thanks in advance !