The Semantics of Tagging - Social Semantics: The Search for Meaning on the Web - page 118

Frequency of tagging for
individual sites

Weight of the tags in the top 25 positions w.r.t. the
total number of tags received by a site

x 10 4

1

7

0.9

6

0.8

5

0.7

4

0.6

3

2 0.5

1 0.4

0

0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40

Time points Time points

Fig. 5.5 ( left ). Cumulative number of times a resource is tagged for each time point. ( right ).
Proportion of times a tag in the top 25 spots of the distribution has been used to tag a resource
to the total number of times the resource has been tagged with any tag

Results for the same set of 500 “Popular” sites described above are shown in
Fig. 5.5 . Note that the tag distributions were reconstructed through viewing the
tagging history of the individual site as available through del.icio.us and collecting
the growth of this tagging distribution over time, thus allowing us to record the
growth of tags outside the 25 most popular.
As seen in Fig. 5.5 , the total number of times a site is tagged grows continuously
at a rate that is specific to each site and this probably depends on its domain and
particular context. Though the results are not shown here due to space constraints, a
similar conclusion can be formulated for the number of distinct tags, given that the
number of distinct tags varies considerably per site and does not seem to stabilize in
time. However for virtually all of the sites in the data set considered, the proportion
of times a tag from the top 25 positions is used relative to the total number of times
that a resource is tagged did stabilize over time. So, while the total number of tags
per resource grows continuously, the relative weight of the tags in the head of the tag
distribution compared to the those in the long tail does stabilize to a constant ratio.
This is an important effect and it represents a significant addition to our analysis of
the stability of the top 25 positions, since it shows the relative importance of the long
tail with respect to the head of the distribution does eventually stabilize regardless
of the growth of tags in the long tail.

5.3 The Effect of Suggestions on Tagging

So far, we have explored the important question of whether a coherent, stable way
of characterizing sense can emerge from collaborative tagging systems, and have
presented several novel methods for analyzing data from such systems. We have