Science is only good if it is properly understood. More traders are now realizing the limitations of backtesting and they are worse than any discretionary bias. Here is an interesting angle:
" Traders who use such products without understanding these realities of repeated backtesting with many degrees of freedom become the victims of their own ignorance and have no chances of ever finding a true edge unless they get to the bottom of this but that requires another edge in the form of an understanding of what must be done to avoid the pitfalls of such processes."
Source
It boils down to the fact that what is at the heart of automated trading, the backtesting routine, is a problematic process as it turns out. This is the reason for a current massive switch to gut trading. If you fail, at least it was your mistake and not some data mining bias thing.
All of this post is 100% true.
Until Siuya posted, all the posters were making this mistake (and probably will not take Siuya's direction).
By using the maths term "degrees of freedom" the solution to the system of the market's operation (STEM based) involves three stages of dealing with degrees of freedom.
Stage I receiving and organizing the raw data degrees of freedom. Six are invloved.
Stage II Increasing the degrees of freedom to "process" information through a logic system. about 70 degrees of freedom are invloved.
Stage III funnelling the 70 degrees of freedom back down to the bare bones
comprehensive "certainty decision tree".
The "gut" thing is a system outside of the STEM since it is a "betting system". betting is done with an emotion based statisticalating. The center pice is HOPE attended by "predicting" in a context called variously "noise", chaos, and/or "randomenss". A sort of "fools paradise".
A. Lo of MIT went through a highly descrabed process into the dungeon of "financial engineering". you can watch him over the years as he "proves" the patterns he sees do not work in any significant manner.
glance at the "head and shoulders". Look at the pertibations applied to prove it is not statistically significant. But what if you use STEM and see it as two consecutive type C trends (the one of the four types that is complete and is not in drift type D)
Suiya suggests the test is made to see if a trend continues, rather than the CW test to determine a trend ended.
Why do not A Lo nor the MBA's know as yet tht there are four distinct types of trends?
The above quoted post is the reason. by using so few egrees of freedom the ype of trends are never differentiated.
Type A incomplete one leg
type B incomplete two legs
type C complete three legs (which is how "The Pattern" is fabricated as the CORE trsding CYCLE)
type D multiples of odd legs greater than three. A complete trend type called DRIFT".
Once a person climbs to a vantage point to be able to see (determine and define using STEM) the sequencing of types of trends, he steps into a new world that is totally different than the world where types of trends are not differentiated.
so now glance at a headand shouldersas two thre leg complete trends where the sentiment reversal is the moment right between the two complete trends.
Now look at the sequence of turn types in the HS. at the junction of each leg there is a turn. The turn types in the HS are a, to b to c to a to b to c.
In terms of "degrees of freedom" this post has introduced the four types of trns the three types of turns and subjuctively, the fact that the sts of like kind items on the sytem of operation of markets always follow Orders Of Events, where b an event is simply a uniquely defined item in terms of STEM.