Dear Andre,
let me say that the algorithms need tuning, so we are not sure we are
doing
the best, but here is the idea:
When a user of reputation 10 (for example) edits the page, the text that
is
added only gets trust 6 or so. It is not immediately considered high
trust,
because others have not yet had a chance to vet it.
When a user of reputation 10 edits the page, the trust of the text already
on the page raises a bit (over several edits, it would approach 10). This
models the fact that the user, by leaving the text there, gave an implicit
vote of assent.
The combination of the two effects explains what you are seeing.
The goal is that even high-reputation authors can only lend part of their
reputation to the text they create; community vetting is still needed to
achieve high trust.
Now as I say, we must still tune the various coefficients in the
algorithms
via a learning approach, and there is a bit more in the algorithm than i
describe above, but that's the rough idea.
Another thing I am pondering is how much a reputation change should spill
over paragraph or bullet-point breaks. I could change easily what I do,
but
I will first set up the optimization/learning - I want to have some
quantitative measure of how well the trust algo behaves.
Thanks for your careful analysis of the results!
Luca
On 7/30/07, Andre Engels <andreengels(a)gmail.com> wrote:
2007/7/29, Luca de Alfaro <luca(a)soe.ucsc.edu>du>:
We first analyze the whole English Wikipedia,
computing the reputation
of
each author at every point in time, so that we
can answer questions
like
"what was the reputation of author with id
453 at 5:32 pm of March 14,
2006". The reputation is computed according to the idea of
content-driven
reputation.
For new portions of text, the trust is equal to (a scaling function
of)
the
reputation of the text author.
Portions of text that were already present in the previous revision
can
gain
reputation when the page is revised by
higher-reputation authors,
especially
if those authors perform an edit in proximity of
the portion of text.
Portions of text can also lose trust, if low-reputation authors edit
in
their proximity.
All the algorithms are still very preliminary, and I must still apply
a
rigorous learning approach to optimize the
computation.
Please see the demo page for more details.
One thing I find peculiar is that adding a text somewhere can lower
the trust of the surrounding text while at the same thing heightening
that of far away text. Why is that? See for example
http://enwiki-trust.cse.ucsc.edu/index.php?title=Collation&diff=prev&am…
- trust:6 text is added between trust:8 text, causing the surrounding
text to go down to trust:6 or even trust:5, but at the same time
improving text elsewhere in the page from trust:8 to trust:9. Why
would the author count as low-reputation for the direct environment,
but high-reputation farther away?
--
Andre Engels, andreengels(a)gmail.com
ICQ: 6260644 -- Skype: a_engels
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