<html>
<head>
<style>
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Verdana
}
</style>
</head>
<body class='hmmessage'>
Hi Jochen.<br><br>> Objekts in the real world can't neatly be categorized into types. The<br>> world is much more complicated than this. So OSM has a different<br>> approach: We just have attributes of objects called tags. Tags tell you<br>> *something about* an object, but they don't tell you what it *is*.<br>> Or, if you want to, you can see it this way: The sum of all the tags on<br>> an object is the type.<br><br>Well, I'm not sure that the kind of objects found on a map can't be categorized by a sufficiently flexible system. Given the name OpenStreetMap, I'd think there's a finite collection of object types that make sense here. That collection will have to grow over time, certainly, but we can be smart about classifying objects without imposing a daunting workload on the mapper. Objects that are deemed "unclassifiable" can rely on the free-form tags.<br><br>Plus, the current system seems to be aiming for more organization than just a free-form collection of tags. Otherwise, wouldn't we just have an attribute called "tags", followed by a delimited series of values?<br><br>If we have [attribute]=[value], I'd expect to see a defined collection of attributes somewhere. As it stands, we seem to have [value]=[some other value]. What constrains the left term, as opposed to the right term?<br><br>How about an orderly collection of attributes (which would cover most of what's going on now with things like "highway=" or "natural=") WITH the option of a free-form "tags" attribute for object types and attributes that fall through the cracks?<br><br>Given that a major goal of this project is to create a repository of data that are machine-readable and -filterable, wouldn't consistency in tagging help quite a bit?<br><br /><hr />Windows Live™: E-mail. Chat. Share. Get more ways to connect. <a href='http://windowslive.com/howitworks?ocid=TXT_TAGLM_WL_t2_allup_howitworks_022009' target='_new'>See how it works.</a></body>
</html>