From: tcmay@got.net (Timothy C. May)
Date: Wed, 25 Sep 1996 21:27:49 +0800
To: cypherpunks@toad.com
Subject: Re: Not reputation again! (Was: The Nature of the Cypherpunks List)
Message-ID: <ae6e375801021004b001@[207.167.93.63]>
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At 6:45 AM 9/25/96, Greg Burk wrote:

>I know, I said I was through arguing "reputation theory" and I really
>thought I was, but this latest impelled me to say more.
>
>tcmay@got.net (Timothy C. May) writes:
>> --Tim May, whose reputation is, like the list, whatever it is, for whatever
>> reasons, and who thus needs no defenders
>
>Indeed, your reputation needs no defenders among those of us who know
>you directly (if electronically)
>
>But here's something for you to think over: If there are such things as
>negative reputations, why hasn't your reputation zoomed to godlike
>status upon the ... let us say unreserved... condemnations of the
>Poster With Nothing Better To Do, if s/he has a negative reputation (I
>presume you would say so)

First off, I certainly don't know what the precise "calculus of
reputations" looks like. That is, how it adds, subtracts, how the reps of
others factor in, etc.

I think studying how it might work--and how it compares to other fields,
such as movie reviews, music reviews, book reviews, etc.--might be an
excellent Masters-level thesis for someone in sociology or even CS (if done
with the proper slant).

However, I would never think the calculus is something so simplistic as: "I
rate Alice's reputation as very negative. Alice just said some bad things
about Bob. Therefore, Bob's reputation will go up a great deal."

More likely, something like: "Alice just said a bunch of things bad about
Bob. Cool. Maybe this Bob person deserves a look."

In other words, smaller steps, with diminishing returns. And with few
sudden movements, except by direct judgment.

>Or you could contend that there's no such thing as collective
>reputation, but I think there are two major flaws: His/her 1-to-1
>"reputations" clearly add up to a collective consensus among us annoyed
>cpunk readers. Even if you contend that reputations in general do not
>behave collectively, it is no defense in this case at least. And I think
>if "reputation theory" predicts no collective behavior, it must be
>pretty weak.

I believe that, to first order, reputation is a tensor. Given N people,
imagine this matrix:

            Alice  Bob   Charles  Daphne  Earl  Fiona  Gloria  Harold

Alice       .99    -.21    .75     .94    .94    .83    -.03    .22

Bob         .72     .96   -.02     .85    .71   -.60     .10    .32

Charles     .82     .02    .97     .90   -.50    .42    -.10    .70

Daphne      .45     .87    .23     .92    .74    .87     .11    .23

Earl        .89     .54    .34     .90    .95    .23     .23    .46

Fiona       .87     .50    .32     .68   -.34    .97     .78   -.15

Gloria      .59     .78   -.23     .15    .29   -.30    -.80    .51

Harold      .65     .03    .34     .78    .51   -.76    -.51    .97


This can be read thusly: Alice has a .99 rating of her own self, a negative
.21 rating of Bob (or Bob's opinions, or his posts, or whatever is being
rated), and so on. Bob has a .72 rating of Alice, a .96 rating of himself,
etc. "Alice(Bob) = -.21"

Now in this example I made up, some various observations can be made.
Nearly everyone rates Harold pretty low, except for Harold. Thus, Harold's
own opinions of others, if expressed, probably won't change too many other
opinions.

Nearly everyone rates Daphne very highly, and her opinions are read
carefully. However, Gloria does not rate Daphne highly...but then Gloria
rates her own stuff a negative .80, so Gloria has some psychological issues
to deal with and others typically rate her pretty low.

And so on.

In the real world, I think we can see how such a matrix could be
constructed, based on either direct inputs (votes) from people, or based on
their apparently positive or negative comments, etc. (For example, it is
fairly obvious that I might give Hal Finney a rating of .90, and Vulis a
-.90. And so on, for others.)

Now is there a "collective reputation"? There are various additive
properties, with easily understandable meanings. (If Harold is in a lot of
kill files, this says a lot, for example.)

Anyway, as I said before, the "calculus of reputations" is not worked out,
so far as I know. Some weeks back I suggested that the mathematics of
belief as developed in "Dempster-Shafer belief theory" has some nice
properties that make it seem a promising area to look into.


....
>Because s/he can *never spend reputation down to zero*.

So you say. I see no reason reputations cannot be negative, in the sense
that not only do I take the opinions of such a person very seriously, I
tend in fact to believe the opposite opinion is more likely. This is a
"negative " reputation. Thus, a reputation can be "spent down" to zero, and
below.

>Frankly, I think you should just admit that your reputation theory is
>flawed and rethink it. I would be interested in hearing it, but what you
>have now is IMHO badly flawed.


--Tim May

We got computers, we're tapping phone lines, I know that that ain't allowed.
---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
W.A.S.T.E.: Corralitos, CA  | knowledge, reputations, information markets,
Higher Power: 2^1,257,787-1 | black markets, collapse of governments.
"National borders aren't even speed bumps on the information superhighway."