Evaluating Simple Node-Fu and Write-up Node-Fu:
The Simple Node-Fu (SNF) and the Write-up Node-Fu (WNF) are both based on
calculating an average of the
mean of a given dataset. In the SNF
calculation, this dataset is the accumulated
XP and as
Pike already
pointed out, this also includes
XP collected through voting.
Indeed, in order to evaluate your node-writing ability, it
may be better to evaluate the accumulated reputation of all the
write-ups. At first, it seems fair to evaluate the reputation
by calculating the average of the mean:
Mean reputation = Σr / NC
Where Σr is the sum of all the write-up reputations, and NC is
the total node count.
However, examination of the Range (defined as Highest Rep -
Lowest Rep) of the write-up reputations shows that there is
generally a big gap between the highest and lowest valued write-up. In my
case it is currently 29, but more extreme examples are plentiful. Since the write-up
reputations are so widely spread around the mean, the mean
reputation is not the correct measure for a person's node writing
ability.
More definitive evidence on the wide spread of the node reputations comes from calculating the standard
deviation of Σr. The standard deviation describes how widely
spread the sample reputations are from the mean. My write-ups have a
mean reputation=4.0, with a (sample) standard deviation=4.6.
This is a huge standard deviation, especially considering that
the standard deviation is actually larger than the magnitude of the
mean. No doubt other noders have similar statistics.
Since Pike's calculation of WNF is also based on a mean write-up
reputation (with a correction for C!'s), this method incorporates the
same inaccuracies that are introduced due to the wide spread of node
reputation. Nodes with a high reputation have a dramatic influence on
the accuracy of the WNF.
Median Node-Fu (MNF):
The problem of wide distributions around the mean is often
encountered in statistics. In these cases, the median is a better
measure of central tendency. The median is the midpoint of a
distribution; half of the observations are below the median, and half
are above it. For example: family income for a country or region is
usually listed at the median, since families with very high or low
income can have a large influence on the mean.
Since the median is less affected by extreme scores (very low-, or
high-reputation write-ups), I propose the use of an alternative index,
the Median Node-Fu (MNF). It is calculated as follows:
- Arrange the nodes in order from smallest to largest node
reputation.
- Determine the node count (NC); the number of write-ups of a
user.
- If NC is odd, then the MNF is equal to the reputation of the (NC+1)/2
th write-up.
- If NC is even, then the MNF is equal to the average (mean) reputation of the NC/2
th write-up and the 1+(NC/2)th write-up.
Example:
Let's take the
Everything User Search output of
Bob, who
made 10 write-ups. Sort them by
Lowest Reputation First:
My favorite X (thing) full -3 2000-10-05 20:05:02
Urk (place) full 0 2000-11-07 21:34:45
John Doe (person) full C! 1 2000-07-28 14:28:53
tire (thing) full 2 2000-09-04 17:45:23
Atari (thing) full C! 3 2000-09-15 11:11:19
Eating out (thing) full 4 2000-12-14 23:06:47
Senor Spielbergo (person) full 5 2000-10-18 10:14:34
Phoebe Snow (person) full 6 2000-10-05 15:48:51
Elm Street (place) full C! 10 2000-11-07 18:23:12
Nude bagpiping (idea) full C! 48 2000-10-09 21:52:16
Bob's
SNF could be anything, since it is not based on
reputation but on
XP. His
WNF is equal to (10 + 76 + 40)/10 =
12.6. Now
Bob's MNF is (3 + 4)/2 = 3.5.
Calculating anyone's MNF
As opposed to WNF, it is easy to calculate the MNF of any user on
Everything, at the price of one
vote:
- Find the user on Everything User Search
- Find out the number of write-ups (NC) of this user
- Display the write-ups, display by Lowest Reputation First
- Page through until write-up (NC-1)/2, and display the write-up (1 is
subtracted from NC, since the first write-up is 0)
- Vote. The write-up reputation will be listed
- Add or subtract one reputation point, depending on whether you
upvoted or downvoted, respectively. This will give you the user's MNF.
Alternative Method:
Open in your browser:
everything2.com/index.pl?count={(NC-1)/2}&node_id=1223826&usersearch=username&orderby=reputation%20ASC
Where {(NC-1)/2} is the median node count (e.g. it is
124 for a user with 250 write-ups), and username is the user you
want to calculate the WNF for. Continue with steps 5 and 6.
Discussion:
MNF is low:
The Median Node-Fu will generally be lower than the SNF
or WNF, simply because it is not affected by extreme write-up
reputations.
Another interesting observation is that the accuracy of the MNF
increases with increasing number of write-ups. Even though the range of
write-up reputation can become very large, it has no effect on the
MNF.
C!'s:
Unlike SNF and WNF, the MNF is independent of C!'s. The reason is that
C!'ed write-ups are already rewarded through longer exposure on the
front page. Good write-ups will receive all the votes they deserve.
"MNF never goes up"
The Median Node-Fu will certainly go up, but it requires a
significant amount of high quality write-ups. On average, your new
write-ups need to gain higher reputation than your MNF. Also, take a
look at low-reputation write-ups and improve them.
Final Remarks:
Use this index only as a personal measure of your write-up
quality, not as a measure to compare to others. The point is not to be
better than someone else; it is to become better than you were. However, since an Everything's Best Users ranking is apparently part of the game, please see Median Node-Fu Product for a further analysis.