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[amibroker] OT: Re: Margin of Error



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Don,

Gentleman of the day.

Please don't post anymore on this issue.
I have got the message.

I have already left the building.

I only checked in to confirm that it still wasn't going on to the 
detriment of the forum and others.

Don't drag Tomasz into it.
He has enough to do and he does a brilliant job of managing a wide 
range of interests and all the various Ami platforms.

You have all had the last word and the last laugh.

Please do not post again and I won't have to ask you to stop again.

BrianB2.


 --- In amibroker@xxxxxxxxxxxxxxx, "Don Lindberg" <dlindber@xxx> 
wrote:
>
>  Brian,
> I am afraid I have to disagree with one of your statements, and I 
quote" The
> reason I can do that is because my ego is not that large". This 
whole 
> educational guru" bit that your are on is nothing more than an 
over-inflated
> ego that likes to see his words in print. I for one am getting 
tired of
> seeing your never ending rants about something that 1) has little 
bearing on
> this forum and 2) that you appear to know little about. Why don't 
you find a
> soap box in some other park to preach from.I feel I am not alone 
in this
> statement, and I do wish Tomasz would step in a put an end to this 
ABUSE of
> our AmiBroker forum. 
> Sincerely,
> Don Lindberg
>  
> -------Original Message-------
>  
> From: Fred
> Date: 11/9/2006 8:49:36 PM
> To: amibroker@xxxxxxxxxxxxxxx
> Subject: [amibroker] OT: Re: Margin of Error
>  
> Brian,
> 
> At least have the courtesy to label your posts of this nature OFF 
> TOPIC ... 
> 
> This is my last post in this thread ... 
> 
> I usually let most of your posts go by because for the most part 
> They're too lengthy with very little meat to bother with but at 
the 
> same time they are also usually innocuous. However, your posts on 
> this topic are anything but innocuous ... There's no "training" 
going 
> on, just diarhea of the keyboard and as far as critqiuing your 
posts 
> go, we did so you just chose to ignore them or more likely didn't 
> understand the critique. I'm sorry if you were offended, but I 
find 
> your posts offering to "teach" others about something you 
obviously 
> know very little about to be highly offensive to the point where I 
> feel I must step in and say so before you drive the lemmings to 
the 
> sea.
> 
> PS ... My comment about your one reply being absurd was not my 
> colorful way of disagreeing ... 
> 
> --- In amibroker@xxxxxxxxxxxxxxx, "brian.z123" <brian.z123@> wrote:
> >
> > Hello Paul,
> > 
> > The IT revolution has brought in a whole new set of paradigms.
> > It is all relatively new.
> > I don't believe any of us fully understand where it will all go.
> > I also think we are only scratching the surface and that we are 
not 
> > using what is available to us now to its full extent.
> > 
> > That applies to this forum.
> > 
> > I am not one of the *internet kids* and they should be lapping 
me 
> > several times over, but they are not.
> > The fact is I am a way more radical than most of the kids who 
are 
> > half my age.
> > 
> > In the brave new world of internet forums, what is training, who 
is 
> > the teacher, who is the student and what format should it take?
> > Who says the teacher has to know what subject we are going to 
> learn, 
> > have all the answers or even give them all to you if he/she does?
> > 
> > As Fred said, *it is all floating around in my head*, where else 
do 
> > I need it to be?
> > I don't need to write it all down for my own benefit.
> > I already know the answer.
> > I am only researching the subject further to put the fancy icing 
on 
> > the cake.
> > 
> > Sometimes in the forum I can change from being the teacher to 
the 
> > student and back again in three posts.
> > The reason I can do that is because my ego is not that large 
that I 
> > can't turn it to my purposes.
> > 
> > As a radical person I don't sit on the sidelines.
> > I actively participate.
> > I have attempted two *internet culture* experiments within the 
forum
> > (keep in mind that I am naive to the ways of forums which most 
of 
> > you understand inside out).
> > 
> > In the first I took on a pro-active role and offered to do a 
little 
> > free admin on the files section.
> > I got absolutely hammered.
> > That is the nature of experiments.
> > I have no regrets.
> > The results of the experiments are safely tucked away in my 
> research 
> > lab.
> > 
> > This time I tried a pro-active discussion with a light 
structured 
> > theme behind it.
> > I was sensing that the experiment was failing so in those 
> > circumstances it is not hard for me to end the experiment.
> > 
> > Don't blame me; the forum is just not up to it.
> > Rest assured the underlying process was spot on, albeit very 
avante 
> > garde as a training method.
> > It was all too quantum for the forum.
> > The mean member wants Newtonian billiard balls.
> > 
> > I would have been delighted if the forum could or would have 
> > critiqed the real points in the topics.
> > Not one single person challenged my propositions that the 
> > optimisation phase might not qualify as a system test because it 
> > involves making subjective judgements, or my silly suggestion 
that 
> > the number and frequency of signals in a test sample, or changes 
> > there-in, might be a symptom of over-fitting.
> > 
> > Not even the *Great Fred*, brought the full force of his 
intellect 
> > to bear on the facts and arguments presented.
> > 
> > Incidentally Fred, it is not curve-fitting, which is a valid 
> > mathematical method, it is over-fitting.
> > 
> > I was not offended by your *absurd* comment; that is just a 
> > colourful way of saying you disagree with the argument.
> > Some of your behaviours and the behaviour of others in the forum 
is 
> > however deeply offfensive to me.
> > 
> > As always some lovely people joined the topic(s) and generously 
> > shared some good information.
> > 
> > If anyone who expressed interest in the subject privately or 
> > publically or who participated constructively in the topics 
wants 
> > some further info please email.
> > 
> > Sometime in the next month or two I will probably email some 
extra 
> > notes out to that group to honour the commitment I made when the 
> > project commenced.
> > I doubt if they will be as extensive or as conclusive as they 
could 
> > have been.
> > 
> > I will be overseas on holiday for a while so I am not sure on 
the 
> > timing.
> > 
> > Please don't engage in any acrimonious debate amongst 
yourselves; 
> > that is the very thing I abhor most.
> > 
> > BrianB2.
> > 
> > 
> > 
> > --- In amibroker@xxxxxxxxxxxxxxx, "Paul Ho" <paultsho@> wrote:
> > >
> > > I agree, there are plenty of other forums to post it to, AB-TS 
or 
> > even
> > > elitetraders. and probably get more thorough examination 
there. I 
> > think the
> > > concept presented needs thorough examination and is nowhere 
near 
> > ready for
> > > "Training" as the originator espoused. 
> > > This is not the right place as Fred has said.
> > > 
> > > 
> > > _____ 
> > > 
> > > From: amibroker@xxxxxxxxxxxxxxx 
> [mailto:amibroker@xxxxxxxxxxxxxxx] 
> > On Behalf
> > > Of Fred
> > > Sent: Friday, 10 November 2006 12:12 PM
> > > To: amibroker@xxxxxxxxxxxxxxx
> > > Subject: [amibroker] Re: Margin of Error
> > > 
> > > 
> > > 
> > > What's the big deal ... Post it in AB-TS where those who 
aren't 
> > > interested don't have to read it ... The main forum is where 
for 
> > the 
> > > most part newbies come to learn about how to make things 
happen 
> > using 
> > > the product and not so newbies come to discuss new features 
and a 
> > > variety of other things realted to the product, as opposed to 
> > hearing 
> > > newbies spout off about concepts they can't quite put together 
> > that 
> > > have nothing to do with the product or its use.
> > > 
> > > I'd be happy to participate unless of course you think 
differing 
> > > points of view are for some reason dangerous.
> > > 
> > > --- In amibroker@xxxxxxxxx <mailto:amibroker%
40yahoogroups.com> 
> > ps.com,
> > > Keith McCombs <kmccombs@> wrote:
> > > >
> > > > BrianB2 --
> > > > I, for one, am very disappointed by your decision to 
> discontinue 
> > > > "Project Based Training". I was looking forward to further 
> > > > installments. Trading is definitely a statistical endeavor, 
> your 
> > > first 
> > > > submission on Margin of Error was, in my opinion, extremely 
> well 
> > > written 
> > > > and "ON Topic". 
> > > > 
> > > > As for your apology, I will not accept it. It is not due. 
Nor 
> do 
> > > I 
> > > > want an apology from those on the forum who were so rude to 
you 
> > and 
> > > to 
> > > > the forum as a whole. I just wish they had acted in a more 
> civil 
> > > manner 
> > > > and allowed you to continue with your presentation. Their 
> > comments 
> > > were 
> > > > rarely constructive (except perhaps to their own egos). If, 
for 
> > > some 
> > > > ideological reason, they didn't agree with you, couldn't 
they 
> > just 
> > > have 
> > > > skipped your posts, with no harm done?
> > > > 
> > > > Perhaps, after a few days, you can reconsider. Please, if 
> > > possible, try 
> > > > to block out the noise and continue on with your 
presentation.
> > > > 
> > > > I am sure that there are others like myself who would love 
to 
> > > hear "the 
> > > > rest of the story".
> > > > -- Keith
> > > > 
> > > > 
> > > > brian.z123 wrote:
> > > > >
> > > > > This topic was part of OT:Project Based Training which 
> > actually is
> > > > > not an OT subject.
> > > > > I put it under OT to be extra polite.
> > > > > It was all part of a project that involved demonstrating 
the
> > > > > principles under discussion in AmiBroker at the end of the
> > > > > discussion.
> > > > >
> > > > > The topic(s) are within both the guidelines for the forum 
and 
> > OT
> > > > > subjects in the forum.
> > > > >
> > > > > Main topics of discussion:
> > > > > - Trading techniques (using AmiBroker to implement the 
> > technique)
> > > > >
> > > > > Allowable off-topic discussion:
> > > > > - Trading in general
> > > > >
> > > > > The project had no more to do with TS than it does, say, 
AT.
> > > > > It had everything to do with trading in general.
> > > > >
> > > > > However I am removing it from the forum on two counts.
> > > > > Firstly, I am customer orientated and I am responding to 
the
> > > > > requests of forum members.
> > > > > I don't agree with your arguments in anyway but I am 
> complying 
> > > with
> > > > > your request.
> > > > >
> > > > > Secondly, and more importantly, some members of the forum 
have
> > > > > breached my personal code of conduct.
> > > > > The environment (of this project) has been made unpleasant 
> for 
> > me
> > > > > and is not conducive to any further effort.
> > > > >
> > > > > That doesn't rule out my participation in other topics.
> > > > >
> > > > > Thanks to the people who contributed.
> > > > > I apologise to anyone who was benefitting from the 
discussion 
> > and
> > > > > who will now miss out on the rest of the *project* 
components.
> > > > >
> > > > > The decision was out of my hands.
> > > > >
> > > > > BrianB2.
> > > > >
> > > > > --- In amibroker@xxxxxxxxx <mailto:amibroker%
> > 40yahoogroups.com> ps.com
> > > <mailto:amibroker%
> > > 40yahoogroups.com>, 
> > > > > "brian.z123" <brian.z123@>
> > > > > wrote:
> > > > > >
> > > > > > Part1 of Project Based Training No1.
> > > > > >
> > > > > > The objective of the project is to introduce new traders 
to 
> > the
> > > > > main
> > > > > > concepts of system design/testing and demonstrate their
> > > > > application
> > > > > > in AmiBroker.
> > > > > > At the same time it is hoped that the ideas presented 
will 
> > > provoke
> > > > > > discussion and provide trading stimulation.
> > > > > >
> > > > > > All of the stages in the design process will not be 
> > demonstrated
> > > > > as
> > > > > > most have already been covered elsewhere in the 
AmiBroker 
> > > support
> > > > > > material.
> > > > > >
> > > > > > A basic understanding of the application of some 
statistical
> > > > > methods
> > > > > > to the trading environment is a pre-requisite.
> > > > > > The opening topics address this need.
> > > > > >
> > > > > > To those who find the subject matter new *the project* 
will 
> > be a
> > > > > > workbook .
> > > > > > To those who have experience in the subject it will be an
> > > > > > opportunity to workshop.
> > > > > >
> > > > > > I would like to acknowledge my indebtedness to the 
academic
> > > > > > community .
> > > > > > I often refer to the material so generously interpreted 
for 
> > the
> > > > > > layperson and made available at websites by academic 
> > > specialists,
> > > > > > particularly those associated with Universities.
> > > > > >
> > > > > > 
> > > 
> *******************************************************************
> > > > > > Margin of Error.
> > > > > >
> > > > > > Back-testing of historical data provides traders with a 
> > sample,
> > > > > > typical of the trade they are testing. From that sample 
> they 
> > > make
> > > > > > inferences about the larger group, or population, of all 
> past
> > > > > trades
> > > > > > and future trades, of the same type, that were not 
included 
> > in
> > > > > their
> > > > > > test window.
> > > > > > Despite the fact that the people who teach them to back-
> test 
> > > also
> > > > > > teach them that the past can not predict the future, 
some 
> > > continue
> > > > > > to act as if it can.
> > > > > >
> > > > > > If the past can't predict the future. How can anyone 
trade 
> > with
> > > > > > confidence?
> > > > > >
> > > > > > The answer is that while the future can't be predicted, 
the
> > > > > > likelihood of some mathematically defined outcomes can be
> > > > > predicted
> > > > > > with a degree of confidence.
> > > > > > Statistics is the mathematical discipline that manages 
that 
> > very
> > > > > > well.
> > > > > >
> > > > > > The caveat is that to apply statistical methods to 
trading
> > > > > samples,
> > > > > > the assumption is made that they are the result of a 
random
> > > > > process.
> > > > > > Where the trading system chosen is biased to non-random 
> > > behaviour
> > > > > it
> > > > > > will be prone to failure if the market acts contrary to 
> that 
> > > bias.
> > > > > >
> > > > > > For that reason system traders are faced with a choice 
> > between
> > > > > > attempting to define market behaviour e.g. a trend, and 
> pick 
> > a
> > > > > > system to suit that, or search for a universal signal 
that 
> is
> > > > > > consistent irrespective of any assumed market bias.
> > > > > >
> > > > > > If statistics can predict the likelihood of future 
trading
> > > > > outcomes,
> > > > > > how accurate will it be?
> > > > > >
> > > > > > *Standard error* or *margin of error* offers traders a 
> > solution
> > > > > but
> > > > > > they are not subjects that are often discussed.
> > > > > >
> > > > > > In his book ,*Design, Testing, and Optimisation of 
Trading
> > > > > Systems*
> > > > > > (John Wiley & Sons, 1992), Robert Pardo raises the issue 
of 
> > the
> > > > > > accuracy of trading *predictions* based on the size of 
the 
> > > sample
> > > > > > used:
> > > > > >
> > > > > > * The sample size must be large enough to allow the 
trading 
> > > system
> > > > > > to generate a statistically significant sample of trades.
> > > > > > A sample of one trade is certainly insignificant, 
whereas a 
> > > sample
> > > > > > of 50 trades or more is generally adequate.*
> > > > > >
> > > > > > He uses Standard Error as a measure of significance:
> > > > > >
> > > > > > StdError = = 1/SquareRoot(sample size),
> > > > > >
> > > > > > 1/SqRt(50) = = 14.1%.
> > > > > >
> > > > > > There is little by way of further explanation provided.
> > > > > >
> > > > > > Applying the formula to a greater number of samples:
> > > > > >
> > > > > > Where N = = the number of trades in the sample
> > > > > >
> > > > > > StdError factor = = 1/SqRt(N)
> > > > > > StdError% = 1/SqRt(N) * 100
> > > > > >
> > > > > > If N = = 2500 the StdError% = = 1/SqRt(2500) * 100 = = 
+/- 
> 2%
> > > > > > If N = = 10000 the StdError% = = 1/SqRt(10000) * 100 = = 
+/-
> 
> > 1%
> > > > > >
> > > > > > A trade sample of 10000 to provide statistical accuracy 
of 
> > 1% is
> > > > > not
> > > > > > easily achievable for traders, although a lot easier than
> > > > > accurately
> > > > > > surveying the eye colour of Polar Bears.
> > > > > >
> > > > > > Pardos equation is in fact, a rounding of the StdError 
> > equation
> > > > > for
> > > > > > a 95% level of confidence:
> > > > > >
> > > > > > Margin of error at 99% confidence = = 1.29/SqRt(N)
> > > > > > Margin of error at 95% confidence = = 0.98/SqRt(N)
> > > > > > Margin of error at 90% confidence = = 0.82/SqRt(N)
> > > > > >
> > > > > > Later in the project I will use a basic random number 
> > generator,
> > > > > > within Xcel, to provide a visual aid that traders can 
use to
> > > > > > understand the *sample* concept and decide for 
themselves 
> > what
> > > > > > constitutes an adequate sample.
> > > > > >
> > > > > > Wikipedia provides some additional clarity on the 
subject:
> > > > > >
> > > > > > http://en.wikipedia 
> > <http://en.wikipedia.org/wiki/Margin_of_error>
> > > .org/wiki/Margin_of_error 
> > > > > <http://en.wikipedia 
> > <http://en.wikipedia.org/wiki/Margin_of_error>
> > > .org/wiki/Margin_of_error>
> > > > > >
> > > > > > *The margin of error expresses the amount of the random 
> > > variation
> > > > > > underlying a survey's results. This can be thought of as 
a 
> > > measure
> > > > > > of the variation one would see in reported percentages 
if 
> > the 
> > > same
> > > > > > poll were taken multiple times. The larger the margin of 
> > error,
> > > > > the
> > > > > > less confidence one has that the poll's reported 
> percentages 
> > are
> > > > > > close to the "true" percentages, that is the percentages 
in 
> > the
> > > > > > whole population.*
> > > > > >
> > > > > > *An interesting mathematical fact is that the margin of 
> error
> > > > > > depends only on the sample size and not on the 
population 
> > size,
> > > > > > provided that the population is significantly larger 
than 
> the
> > > > > sample
> > > > > > size, and provided a simple random sample is used. Thus 
for
> > > > > > instance.......the running example with 1,013 random 
> > > samples......would
> > > > > > yield essentially the same margin of error (4% with a 
99% 
> > level 
> > > of
> > > > > > confidence) regardless of whether the 
> > > population..........consisted of
> > > > > > 100,000 or 100,000,000.*
> > > > > >
> > > > > > In short the tail of the trading system sample is 
swinging 
> > the
> > > > > > trading system cat.
> > > > > >
> > > > > > BrianB2
> > > > > >
> > > > > > The material contained in this topic is for educational 
and
> > > > > > discussion use only.
> > > > > > It is not intended as financial advice and should not be 
> > > construed
> > > > > > as such.
> > > > > > The author is not an accredited academic or financial 
> > advisor.
> > > > > >
> > > > >
> > > > >
> > > >
> > >
> >
>




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