Hello!

I am working currently on my dissertation and a part of it concerns some stats issues that I am not familiar with.

Specifically I need to perform Time Series Forecasting and I am considering using SPSS. Actually I have installed SPSS Statistics 17.

The data I am using is ratings for a movie over time, comes from xls or csv files and includes two columns: one with dates, and one with movie ratings.
A detail about dates is that they are not continuous and the records of my data set are about 1500. More specifically the data is like that:

04/04/2004 5
05/04/2004 4.5
07/04/2004 2
10/04/2004 3.3333
.
.
.

So from these 1500 pairs of values(date,rating) I would like to use 1200 as training set, and based on it, to predict ratings for the remaining.

I select the cases that I want in Data->Select cases option, and then I click on Analyze->Forecasting->Create Models.
When the Time Series Modeler window appears, I leave as method Expert Modeler, and from other tabs I select the forecast values to appear on my graph.
The result I get regarding forecast values, is a straight horizontal line.

Do I miss something in the whole process? Is this the right approach concerning time series forecasting or is there anything else that I should use?
I have no idea about SPSS and what I should use, so please help! (In fact I didn't even know about SPSS, and now my time constraints are extremely limited).

Thanks in advance and sorry for the long post.

erm, I've never used this function in SPSS. My hubby is a statistical modeller in the civil service though and does lots of forecasting, he always uses Excel for it, wouldn't touch SPSS.

Sorry I know that's not much help, but there may be some excel forums that can help out there

Are you sure you want to be doing time series modelling on this?

And statistical modelling in Excel?!?!? I think my eyes have just started to bleed! Aghhhh it burns , it burns!!!

yeah DanB, I think he has to know 'vba programming' to do it - I have no idea, he talks about these things and I just go into a daydream about kittens.

Although I know you can do time 1 time 2 differences in regression some how, which you could do in SPSS,not sure how though. Best bet would be to look at some journal articles that have also used it.