What’s wrong with hierarchies?

Hierarchies gives the impression that something can only belong in one place, like a paper folder in a file cabinet.

Hierarchies infers a structure of parent and child, even when that's not true.

If we don’t know exactly which parent something is a child of, we have to start digging: the picture was taking during our vacation, but was it in June or July? The 21st or 22nd?

In hierarchical structures it can be hard to get an overview, because things are hidden inside eachother. An example of this is clear when comparing Picasa with Windows Explorer. When you open a folder in Explorer, you can't see the photos in the folder you were in before. So if you open "March 2006" you can see "April 2006". Picasa shows all photos in one pane, regardless of hierarchy so that March and April is visible at the same time.





Another problem visible in the Explorer example, is the Back-Back-Back-problem. In many interfaces you go into a folder, and into a folder and into a folder again. If it's a dead end, you have to back up three times or hit the Menu key or something and then start digging.

If we have to store something in just one place, it requires standards and knowledge to place it right, for instance like librarians arranging books in the Dewey Decimal System.

Hierarchies are best for arranging smaller amounts of objects. As the number of websites increased, Yahoo went from being a directory to become a search engine.

So while Yahoo's taxonomy places me here Arts > Design Arts > Industrial Designers, Google means that I belong here Business > Industries > Design > Industrial Designers. And who's to say that one's right and the other's wrong? Maybe people looking for me here:
World > Norsk > Referanse > Utdanning > Universitet og høgskoler > Vitenskapelige høgskoler >... Coming to a TV near you :)