apothanousa
- user since
- Sun Aug 18 2002 at 01:43:20 (6.2 years ago )
- last seen
- Sun Sep 26 2004 at 23:26:45 (4 years ago )
- number of write-ups
- 17 - View apothanousa's writeups (feed)
- level / experience
- 1 (Initiate) / 222
- mission drive within everything
- node what everyone should know and doesn't seem to. Reach level 4. C! something deserving. Retire.
- specialties
- Things my mother taught me
- school/company
- The Penguin Juice Co., Inc.
- motto
- motto quia mottandum
- most recent writeup
- logical punctuation
Warning: everything on my homenode is obnoxious and should not be readFor if it weren't, it would be in a real node. QED. Thank you for your attention.apothanousa's Most Frequent CoolersThanks to the following people for C!ing my writeups:
Cools Perpetrator
Nitpicks about E2:
Interpreting the Honor RollThe Honor Roll computation works by approximating merit by a normal distribution. But the next step is, bizarrely, to compute your LF in terms of the value of the pdf at your merit, rather than its integral? Okay, sure, it's invariant in the sense that it corrects for mean and s.d. in the way you'd want it to; but the effect isn't that of the graph Professor Pi draws in the Honor Roll superdoc. If you draw the graph to show LF against distribution (i.e. the one which tells you approximately how many noders get what LF) you find that it's constant for a longer time and drops more sharply towards the end:
1.00 |.....*******
| ... *****
| ... ****
| .. ***
0.95 | ... ****
| .. ***
| .. ***
| .. ***
0.90 | .. ***
| .. **
| .. ***
| .. ***
0.85 | .. **
| .. ***
| . **
| .. **
0.80 | .. **
| . **
| .. **
| .. **
0.75 | . **
| .. **
| .. **
| .. ***
0.70 | ... ***
| .. **
| .. **
| .. ***
0.65 | .. **
| .. **
| ... ***
| ... **
0.60 | ... **
| ... ***
| ... **
| .... **
0.55 | ..... ***
| ...... **
| ......... ***
| .................*
. = Curve shown in in Honor Roll (horizontal axis = merit, from 0.0 to 2.0 standard deviations) * = Curve as perceived by noders (horizontal axis = distribution, from median noder to best noder)Both curves represent only the top 50% of noders; the bottom 50% correspond to a constant 1.00 to the left. Note that because of the different horizontal scales (which are the whole point) it doesn't strictly make sense to make comparisons like “one is higher than the other”, though I've tried to align them reasonably. The point is really the shape—facts like ‘over 75% of noders have LF above 0.80’ which you can read off from my graph, but about which the graph in Honor Roll is highly misleading. Note that I am not advocating a change to the Honor Roll system, because I believe firstly that the general idea is an excellent improvement to E2, and secondly that the precise formula currently in use works well. But I find the graph above to be the only convincing evidence for the latter—I didn't believe it from reading the Honor Roll superdoc. Professor Pi writes: “[...] I think plotting it against distribution is actually more misleading. Because the norm. dst. is only an approximation of the actual distr, the graph (which is only an *example* on Honor Roll ) you will draw incorrect conclusions such as "x% has a LF above y". And I don't agree with your statement below the figure "curve as perceived...". People don't perceive this curve in terms of distribution, but in terms of what they can observe directly: their merit and LF score. I have some ideas on other ways to present this data, so that the average noder can understand it. That will eventually end up in a FAQ. [...]”To some extent I think Professor Pi and I have different objectives. Professor Pi, being practical, sane and rational, having administrative obligations, and observing from experience that the system works well, infers that there is no need to change it, and is therefore expending effort in ensuring that noders understand the system that has been implemented. I, being impractical, pedantic and rational, having little practical experience of the system, and believing that no convincing quantitative justification for the formulæ has been given, have tried to determine theoretically whether the system works well, have in my opinion shown that it does1 (by drawing the graph), and have inferred that there is no need to change the system. 1As Professor Pi points out, the distribution of merit is not necessarily normal. But if the normal approximation is good enough for him, it's good enough for me (he says, having previously cast aspersions on one of PP's formulæ.)
For those who either doubt my computations or simply can't work out what the hell I think I'm doing, here's the source with which I drew the above graph:
My ekw settings, as if you caredekw_alinkcolor="#f038c0"; ekw_bgcolor="#f8f8f8"; ekw_headingfont="Tahoma,Verdana,Helvetica,Arial"; ekw_linkcolor="#1038c0"; ekw_logoaccenttext="#ffff90"; ekw_logobackground="#3058e0"; ekw_logoborder="#000000"; ekw_logofont="Tahoma,Verdana,Helvetica,Arial"; ekw_logofontsize="17pt"; ekw_logomaintext="#f0f0f0"; ekw_monofontsize="12pt"; ekw_oddrowcolor="#d0d0f0"; ekw_textcolor="#000000"; ekw_textfont="Arial, sans-serif"; ekw_textfontsize="12px"; ekw_vlinkcolor="#f038c0";If the result doesn't look good to you, it's your own fault for not being red-green colour blind. (Or your monitor needs gamma correction, or both.) |