This post is to amplify a cryptic remark I made re hashtags.

Firstly how do you find the ‘meaning’ of a hashtag? For example I came across the hashtag #TechWeekly in Aleks Krotoski’s tweets. What did this refer to? There seemed no easy way to find out except to put it into Google! Or am I missing something?

So hashtags are OK for closed groups – classes, conferences etc. But there needs to be a shared context for meaning. Twitter doesn’t automatically provide this. So simply putting a ‘#’ in front of a word may well not help a reader.

One of the purposes of hashtags is to facilitate search. If we do a few simple trials on searching in tweets containing strings such as dgr, #dgr, dgr.abc, #dgr.abc, dgr.abc.def, #dgr.abc.def, ?dgr, ?dgr.abc, ?dgr.abc.def with search strings dgr, #dgr, ?dgr, dgr.abc, #dgr.abc we find the following:

* Search with a string that does not contain a ‘#’ simply compares all text in all tweets and reports those where there is a match of the search string with a string in the text
* For this purpose a string in a tweet is delimited (presumably) by non-printing characters, and certainly the punctuation characters ‘#’, ‘.’ and ‘?’.
* Search with a string that starts with a ‘#’ reports only tweets that contain only the search string followed by a space.

This last result indicates the special significance that the Twitter software gives to the ‘#’ character but also indicates its limitations. We can go beyond the use of a single ‘#’ as a signifier, as in a hashtag. The # is useful to indicate to a community a text string of interest and over time will by accretion collect a set of associations which may give it a contextual meaning for that community. With 75 million registered users of Twitter it seems to me doubtful that the community as a whole could come up with a meaningful and unambiguous concensus for most words. For a group that was effectively closed (attendees at a conference or event) then a common hashtag would have meaning.

But the above results indicate that a finer grain is possible and the style of web addresses, with progressively finer domains separated by full stops, is obviously possible. For example a tweet containing the string #xyz.abc.def will be picked up by a search string xyz.abc. Of course web addresses are organised in the sequence less to wider significance, left to right, whereas for organisational information it is more natural to have the left to right order representing more specialisation.

Thus it is quite possible for, say, tweets for a class to be broken down into categories and even individual tweeters to append their user name (or indeed any other name) to their tweets for quick identification.

David

@David Try http://hashtag.org – they are trying to put together a directory of hashtags. Could be the next (domain) name gold rush if they get critical mass. Not that there is any enforcement of ownership in use.