The most common outlier
treatments in finance are winsorizing, trimming, and dropping (referred to hereafter as WTD).
" argues, this constant churning--this trespassing of the borders of high and low, this teetering between the unknown and the famous--is essential to the dynamism of American art itself.
"Joint Estimation of Model Parameters and Outlier
Effects in Time Series." Journal of the American Statistical Association, 88, 1993, 284-97.
may position themselves on the fringe, seeking to gain reputations as innovators.
Before applying the LOF algorithm, it is necessary to specify two parameters: the number of closest neighbours k and the threshold value, above which it is considered that the record is outlier
. When choosing the number of closest neighbours, it is recommended that k value would be equal to square root of all data, used for the model training.
For the point outliers
, results from outlier
method #1 (Standard Deviation), #2 (Quartile), and # 3 (Grubbs' Test) are 7, 17, 12 outliers
From a practical point of view, it is well known that Pearson's correlation is not resistant to outliers
and thus choosing weights in (2) based on this correlation will cause uncertain and deceptive results.
The relative prediction error term indicates whether the point is an outlier
. The larger value of [r.sub.t] means the current point is more suspicious to be an outlier
Velleman, "BACON: blocked adaptive computationally efficient outlier
nominators," Computational Statistics and Data Analysis, vol.
Detection Using Invariant Coordinate Selection.
Unlike other outlier
detect method (such as the traditional AR model detection method), the outliers
detect method proposed in this paper does not need to set the detection threshold.
It works on the premise that many outliers
are unaware they are an outlier
, no one wants to be an outlier
, and confidential, collegial education and peer mentoring within a medical specialty society can reduce unnecessary variations in care.