Author:  brick_projects  Posted:  Jul 20, 2016 08:53  Subject:  standard deviation on price indices  Viewed:  201 times  Topic:  Suggestions  Status: Discarded Cancel Reply

BrickLink ID Card brick_projects (3648) Location:  Belgium Member Since Contact Type Status Collage Feb 26, 2009 Seller  Store: Brick Projects FREE📦📫 BE

Please implement standard deviation. By eliminating the (small number)% cheapest and (small number) % most expensively priced lots, the average price index would be "more statistically significant" in scientific terms ( less error margin ). This is only necessary for items that have at least e.g. 10 distinct lots for sale. Why this suggestion ? Yesterday i noticed one particular seller set all his prices at ( BL avg x 10000 ). This caused average price index "lots for sale" to be inflated at least tenfold. Someone else suggested he made a mistake in currency. If this one shopkeeper persists, unwanted "extreme" inflation may occur on several very common items, and those lots - for sellers not paying attention when adding to their inventory - might become impossible to sell.

Message Has 7 Replies:

Re: standard deviation on price indices - FigBits (3560)

[...] Voted no. I do not want BL to remove any data. If you want to suggest *adding* information, I would be fine with that. (Such as adding the median price.) To [...] (95 months ago, Jul 20, 2016, to Suggestions)

Re: standard deviation on price indices - yorbrick (1185)

[...] There is the real problem here. (95 months ago, Jul 20, 2016, to Suggestions)

Re: standard deviation on price indices - jancg (377)

Voted no. Same argument as others: don't hide any information. If you want a smarter pricing routine, build it yourself using the BL API. (95 months ago, Jul 20, 2016, to Suggestions)

Re: standard deviation on price indices - garbanzo (322)

[...] I don't understand the downvotes. Implementing this doesn't necessarily mean replacing current data. I voted yes, this makes sense. I would also like to see 6-month [...] (95 months ago, Jul 20, 2016, to Suggestions)

Re: standard deviation on price indices - ToriHada (8887)

I voted yes. This suggestion has been made many times before, including by myself. There is no reason why users cannot have the OPTION to exclude extreme data points when using [...] (95 months ago, Jul 20, 2016, to Suggestions)

Re: standard deviation on price indices - Made_In_Bricks (3994)

voted no - better suggestion, allow users to program how they want the price guide displayed via their own settings, if users could define the rules they want everyone would [...] (95 months ago, Jul 20, 2016, to Suggestions)

Re: standard deviation on price indices - wildchicken13 (876)

[...] Rather than excluding data points from the calculation of the mean, why not add a median to the price guide? The median is much more resilient to outliers like the example [...] (43 months ago, Nov 17, 2020, to Suggestions)

21 Messages in this Thread:

 Msg 1 « - brick_projects (3648) 95 months ago Jul 20, 2016 to Suggestions
 Msg 2 - FigBits (3560) 95 months ago Jul 20, 2016 to Suggestions
 Msg 3 - jeslego (1050) 95 months ago Jul 20, 2016 to Suggestions
 Msg 4 - FigBits (3560) 95 months ago Jul 20, 2016 to Suggestions
 Msg 5 - yorbrick (1185) 95 months ago Jul 20, 2016 to Suggestions
 Msg 6 - FigBits (3560) 95 months ago Jul 20, 2016 to Suggestions
 Msg 7 - jeslego (1050) 95 months ago Jul 20, 2016 to Suggestions
 Msg 8 - FigBits (3560) 95 months ago Jul 20, 2016 to Suggestions
 Msg 9 - jedvii (666) 95 months ago Jul 22, 2016 to Suggestions
 Msg 10 - yorbrick (1185) 95 months ago Jul 20, 2016 to Suggestions
 Msg 11 - jancg (377) 95 months ago Jul 20, 2016 to Suggestions
 Msg 12 - ToddMyers (356) 95 months ago Jul 20, 2016 to Suggestions
 Msg 13 - jancg (377) 95 months ago Jul 20, 2016 to Suggestions
 Msg 14 - Leftoverbricks (2225) 95 months ago Jul 20, 2016 to Suggestions
 Msg 15 - garbanzo (322) 95 months ago Jul 20, 2016 to Suggestions
 Msg 16 - jancg (377) 95 months ago Jul 20, 2016 to Suggestions
 Msg 17 - yorbrick (1185) 95 months ago Jul 20, 2016 to Suggestions
 Msg 18 - ToriHada (8887) 95 months ago Jul 20, 2016 to Suggestions
 Msg 19 - Made_In_Bricks (3994) 95 months ago Jul 20, 2016 to Suggestions
 Msg 20 - FigBits (3560) 95 months ago Jul 20, 2016 to Suggestions
 Msg 21 - wildchicken13 (876) 43 months ago Nov 17, 2020 to Suggestions