[Routing] Crowdsourced costing - offer of writing a client+metric for it

[Sascha Silbe]

On Wed, Dec 03, 2008 at 07:50:26AM +0100, Marcus Wolschon wrote:

> * day = (weekday,weekend,holiday)
> * time = (night,morning,afternoon)
> ** sub-time = (early,mid,late)
Unfortunately, that's too coarse. You'll miss things like "Shops are 
closed on Wednesday, so much less traffic then". Or the yearly recurring 
traffic increase due to christmas insanity...

> * we do not receive user-identifications at all
> * the IP and upload-time are stored to revert manually detected 
> vandalism
Those two are mutually exclusive. Though german ISPs tend to assign 
dynamic IP addresses so they can sell static ones for more money, it's 
not the case everywhere. Even then, given usual IP address lifetimes 
(24h), the tuple (IP address,time) is enough to identify a user if 
correlated with other sources (e.g. emails).

Sorry for critising in a destructive way, but I don't have better ideas 
myself.
There's always the risk of even a single upload violating the anonymity 
of the user (even with fully-anonymous uploads), as the driving pattern 
may be distinctive enough (e.g. driving from one farm to another in a 
very sparsely populated area).
Even for "regular" cases (let's say driving to work in a large company 
in a large city) pseudonymity (=user names or IP addresses) won't be 
enough to ensure privacy once we reach a certain volume of data (you can 
correlate with information like ill-times, vacation times, ...).

Summary:
- there are some cases where anonymity is not possible at all
    - => need to warn users about that
- in the general case, the server must anonymize the data (either by not 
storing user-identifiable data or by not handing it out)
    - => the users have to trust the server


PS: The rest of your proposal looked OK to me (apart from using bloat 
like SOAP, but that's a matter of taste anyway). I'd say go on and set 
up such a server. Let's gather some experience from using it and 
analyzing the data it collected. Before we do that, it's hard to know 
what data is useful; kind of like crystal gazing. I dare say we'll need 
a second version anyway, even if we try to imagine every possible usage 
scenario now.

CU Sascha

-- 
http://sascha.silbe.org/
http://www.infra-silbe.de/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 481 bytes
Desc: Digital signature
URL: <http://lists.openstreetmap.org/pipermail/routing/attachments/20081203/475d2819/attachment.pgp>