--- In FairfieldLife@yahoogroups.com, akasha_108 <[EMAIL PROTECTED]> wrote: > > --- In FairfieldLife@yahoogroups.com, "authfriend" <[EMAIL PROTECTED]> wrote: > > > > --- In FairfieldLife@yahoogroups.com, 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. > > 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. > *or whatever pre and post periods they used. > > I thought you yourself argued previously that long term data was not > necessary (like abortion rates) because the effects were shown in a > short-term time frame. Perhaps I misunderstood your prior point. Yes, you did. Please go back and review, because I can't tell where your misunderstanding lies. > 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*. > See my adjacent post. I think the longer term model was a second > stage of analysis used to control for weather. No. For at least the fifth time now, the weather protocol was decided on and announced before the intervention even began. > See my adjacent post. Its the only explanation that makes sense to > me at this point. Actually reading the study would be halpful > though, instead of specualation. Well, yes. Your speculation is pretty much useless, I'm afraid. ------------------------ 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/
