The directory vs search argument was long settled when Google triumphed over Yahoo 15 years back. Search is wonderful and is magical as a navigational tool.
But, search is not a lone warrior. It needs help in many places. A good example of this is on the desktop. Search on desktop has been bad (the default Windows and Ubuntu search, OS X seems much better). Google Desktop Search promised a lot, but died midway. So, we kept making folders even 15 years after search went mainstream. Folders give us more control, and familiarity with the interface. And, we love things which play well with our folders. Hi, Dropbox !
But, I must be insane to take cues from desktop since we are in the post-PC era. Searching for an app works pretty well on iOS/Android. Still, people keep making folders.
Photo by Nick Paden from http://branch.com/b/what-s-on-your-iphone-home-screen#AvdGFottp4g
Collections are making a comeback on the web too. From Google+ (which allows you to send your post to collections of people) to Pinterest to Amazon, they are everywhere. It is their ubiquitousness that pushed me from not adding them to Allotrop.
I believed that the semantic model of linking nodes together is better and more usable. But, in hindsight, it proved to be very difficult to make a good UX for linking nodes together without making it too much extra work for the user. I also realised that collections are the easiest way for users to provide additional context to their posts.
And so, collections are now a core part of Allotrop. Every user gets started with two default collections - Things I Use and Life is Random. The first is for all the things you use to get stuff done while the latter is for all the random things you find interesting.
This is an early release and a lot of additional features like following a collection, and moving a post from one collection to another will be available soon. You will be then able to move your existing posts from the Life is Random collection where they reside now.
The vision of helping people explore the most interesting and useful information using linked data is still at the core of Allotrop. Collections are another way of helping people achieve this.