Date:         Sat, 10 Sep 2005 00:58:02 -0400
Reply-To:     Richard Ristow <wrristow@mindspring.com>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Richard Ristow <wrristow@mindspring.com>
Subject:      Re: multiple regression model
Comments: To: Omar Farook <omarfdawood@yahoo.com>
In-Reply-To:  <20050910041157.89343.qmail@web90206.mail.scd.yahoo.com>
Content-Type: text/plain; charset="iso-8859-1"; format=flowed

At 12:11 AM 9/10/2005, Omar Farook wrote:

>I have multiple regression model consist of one dependent and 7
>independent variables. Sample size =12.

By most rules of thumb, that is far, far too small a sample. The lowest
I can recall seeing recommended is 5 cases per variable -- sample size
of 35, for you.

>My question is, in this case is it correct to expand the sample size
>and rerun the same model or I should look for new independent
>variables?

CAN you expand the sample size? Where does your data come from?

In the same vein: Where did you get your model in the first place?
"Looking for new independent variables" is useless, unless you have
some theoretical reason for choosing the new ones.

Could you tell us what your problem is? What's the dependent variable;
how did you choose the independent variables; what's the source of your
data?






>Bu using SPSS I have got the figures below.
>
>t  statistic of the 7 predictors variables are
>­1.728,2.513,-1.580,-0.604,-0.667,2.627 and 1.953.
>
>Sig are 0.159,0.066,0.189,0.578,0.541,0.059 and 0.123.
>
>Sample size =12.
>
>According to my knowledge I should look for a t values  below ­2 or
>above +2 and  Sig or p-value of less than 0.05 is considered
>significant.
>
> From the figures above we see that there is no liner relationship
> between the dependant and an independent variables.
>
>
>
>
>Hope I was clear enough.
>
>Thanks in advance.
>
>
>
>Omar
>
>omarfdawood@yahoo.com
>
>
>
>---------------------------------
>  Click here to donate to the Hurricane Katrina relief effort.