--- In [email protected], akasha_108 <[EMAIL PROTECTED]> wrote: > > --- In [email protected], "authfriend" <[EMAIL PROTECTED]> wrote: > > > > --- In [email protected], akasha_108 <[EMAIL PROTECTED]> > > wrote: > > > > > > --- In [email protected], "authfriend" <[EMAIL PROTECTED]> > > wrote: > > > > > > > > --- In [email protected], akasha_108 <[EMAIL PROTECTED]> > > > > wrote: > > > > <snip> > > > > > So when separate models are used to predict crime, distinct > > from the > > > > > intervention model, its unconventional. Its not needed, unless > > there > > > > > were severe data problems. Doing so weakens the predictive > > power of > > > > > the model(s). > > > > > > > > > > There is nothing in the data issues, at first glance, that > > suggest > > > > > why multiple, models were used. > > > > > > > > I have no idea what you're talking about when you > > > > refer to "multiple models." I never said anything > > > > about multiple models. > > > > > > see adjacent post in my response to LBS. > > > > Doesn't help. > > So you still hold ony one model was used?
I said: "I have no idea what you're talking about when you refer to 'multiple models.' I never said anything about multiple models." > You said it was an ARIMA model, so it was a multivariate AR > IMA model that controlled for weather and croime factor variables? I suggest you restrict your questions to those you think I might be able to answer. Saves time and space. > > > > You seem to say the prediction based on past trends > > > > was unnecessary; but then to what do you compare the > > > > actual crime rate during the period to determine > > > > whether and how much it's been affected? > > > > > > If it was a short term model, then crime rates would be compared > to the pre course "one month"* and the post course "one month". These > would be control periods (not necessarily good ones, but thats > another story.) > > > > They didn't do that because they wanted to control > > for seasonal variations. > > So why did they have a pre and post period? ?? Why not? > > > If they had the pre and post periods, why did they need the "5 year" > > > (or what ever longer term model) to estimate the crime rate without > > > intervention? They had the "control" periods, pre and post. They > > > didn't need to estimate a non-intervention period. > > > > Pre and post aren't "control" periods because they > > take place at *different times of the year*. > > So they did not use pre and post periods? OK, you don't want to discuss this in good faith, for some reason. Forget it. ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/JjtolB/TM --------------------------------------------------------------------~-> To subscribe, send a message to: [EMAIL PROTECTED] Or go to: http://groups.yahoo.com/group/FairfieldLife/ and click 'Join This Group!' Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/FairfieldLife/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
