hi guys,
im currently analyzing my data using SPSS and generally regression,

has anyone done this,? I could use some tips...

thanks!

I have done regression analysis for my data with SPSS, don't profess to know much but what are you after?

thanks!

well, a simple question, i'm confused regarding confidence intervals...i'm running a logistic regression but I'm not sure what is the significance of the interval to my coefficient, what if the interval contains 1 in it?

When I read back on my notes for logistic regression the confidence interval was left blank.  I too am not sure what this would mean for logistic analysis. I tended to stick with linear regression for my data which I find easier to manage :$  Sorry not a specific answer. Do you have access to statisticians at your uni to ask, this is where most of my help came from.

Hey Billy, I've just spent most of my day doing multiple regressions on SPSS. I am using linear regressions, and I have to confess I don't know much about logistic regression, but I would definitely advise seeing a statistician if you're not sure. I've had a meeting with our statistician today and even though I know how to do regression there are all sorts of issues that have cropped up wth my data that I hadn't really thought about before. Now I'm having to re-run some of the regressions and am in my last month of writing up- I would definitely get your stats checked out earlier rather than later so you don't end up having to change things at last minute! Best, KB

Are you calculating odds ratios? If the confidence interval includes 1 then it suggests that the effect you have observed (i.e. the odds ratio) is not statistically significant. You should always report an effect with a confidence interval plus some kind of statistical test (e.g. a Chi squared test which gives a p value).

I'm calculating both a logistic regression and a linear regression, depending on the dependent variable.....

almost all intervals contain 1 if i'm not wrong, is that possible? surely not all relationship must be rejected..!

my sample is 103 (out of 700) is that not large enough? must be !

Whether or not that is a big enough sample size depends on what you're measuring and how much of a difference you're hoping to find between the (controls and experimental) groups.

It's hard to give you exact advice via a forum. I suggest that you try to talk to a statistician in your department who will be able to look at the whole picture with you.

There is a video that demonstrates how to perform and interpret a logistic regression in SPSS on youtube:

http://www.youtube.com/watch?v=OvQShzJ7Sns