Trends

It mangled the second link: http://www.google.com/trends/explore#q=Drupal

I have to admit to a great deal of skeptisism with all of the "statistics" people bandy about in our field. I wasn't going to reply here, because I only have my personal opinion to go on, but then I found this report rating programming languages by number of hits on search engines:

http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html

Based on this monthly index, Javascript is a slightly less popular language than TRANSACT-SQL.

If you look at the second figure on that page, the long term trends for the current top ten languages, you might notice a correlation with the Google Trends graph (Paul's 2nd link). Just as Drupal peaked in 2009 and began declining more significantly in the 2nd half of 2011, PHP itself was suffering an almost 1/3 drop in popularity in the TIOBE index.

Now, I still have nothing more than my personal opinion here, but these graphs strike me as being not very relevant measurements - but easy to do!

If you look at the Google Trends graph, there are two peaks of interest in 2009 and 2011. My hunch is that these represent the huge influx of people discovering Drupal 6 and getting going with it from scratch, and the release of Drupal 7, and figuring out how to deal with entities and fields. The D7 bump is lower than the D6 bump because D7 builds on top of many ideas that were honed in D6.

It has been almost 3 years since then, and people have gotten comfortable with D7, so that they need to search less for each project. They have also found other resources, like local DUGs and IRC.

If my personal opinion is at all on track, then the Google Trend graph will show a significant bump for 6 months or so after D8 is released.

So, there's a hypothesis and a testable conclusion. Let the real science begin!