What is modelling?

[sa7med]

It's no coincidence that backtesting is also called hindcasting.

True predictive modelling (aka the useful one out of the many types of modelling) is beyond the intellectual capabilities of everyone I've seen on this forum, except one person who only appeared here very fleetingly. I don't think anyone here even has a decent maths degree, unless they'd like to admit to it now...and be swamped with requests for help.

But on a more helpful note, if you wanted to look at predictive modelling seriously, I suggest going down to your local University and putting a card on the notice board asking for (paid) help. There's bound to be someone who can give you a steer, but I'd brush up on your basic calculus first, otherwise you might not get much from it.

Round here you'll only get riddles and if you're very lucky, some dubious o-level maths, what you won't get are postings that either withstand mathematical rigour or even have enough detail to begin that process.

Thanks for your reply Shaun. Yes indeed, Im prepared to do some real learning to master this, but like I said I need to learn what to learn! I was a math minor in college but virtually no statistics in there. A lot of good that's done me! It seems a lot easier to do now a days with all these python libraries. Still, you have to understand what the hell you're doing.

[sa7med]

Backtesting is looking at Stonehenge and realising that it predicts where the sun is going to rise and fall at critical times of the year.

Modelling is predicting the next solar eclipse on Stonehenge but also building a probe that explores the sun and planets of the solar system because you know how it works and can re-run your models endless to make sure.

Peter do you remember the textbook you recommended a while back? It was called something like: Statistics for everyday applications or something like that

[ShaunWhite]

but like I said I need to learn what to learn!

That is THE problem with this stuff, I totally sympathise and have the same problems.
On the one hand it's vague and fluffy concepts, and then when you try to do some study, the maths gets pretty crazy pretty soon.

The starting point is defining the problem to which you need an answer, easier said than done.

Even doing 101 stuff like plotting a trend isn't as easy as people imagine, I vaguely remember the problem of Anscombe's Quartet (my maths exams were nearly 40yrs ago and I failed). It's 4 sets of data and using a std linear regression, they all plot the same trend...which is obvioulsy less than ideal. The exam question was to suggest a more appropriate type of regression analysis for each one. I'm no wiser 40yrs on, #1 & #2 are fine but I still can't do #3 or #4.

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