Organizing large collection of things - usability and UI point of view

Question

In our application we have a repository that contains things (they are called methods and queries, but this is not particularly relevant for this question). Each thing has a title, description (though some may lack both) and some other data. Users save things to repository and load and use things from repository.

I wonder what is the best way to organize the repository from usability point of view. There seems to be two major approaches. The first approach is to put things in folders, subfolders and so on, and have a hierarchical structure similar to a filesystem. The second approach (that has become fashionable) is two have a flat space and assign zero or more tags to each thing, so that users can view a list of things for a particular tag.

Currently we use flat space, tags and search. It appears to be somewhat unmanageable. I am not sure if switching to folders/subfolders will make it better.

I would like to learn more about the pros and cons of each approach and what properties of the collection and the things themselves suggest using one or another approach or a combination of both. If anybody can point me to some studies or discussions of those, I would really appreciate that.

Answer 1

There is no reason you can't use both methods. To some extent finding things is dependent upon what the thing is and why it is being looked for. A hierachical design can work well when somebody knows what they are looking for and a tag / keyword based system can work better when the structure is less obvious.

Also a network structure that links similar things can also be very good as you can see with the internet or a wikipedia.

Answer 2

I use the law of symmetry to help me in this situation.

First you build the tree like structure in the back end and then build the tagging system for the front end.

You use both to organize your data collection.

Answer 3

A tag cloud works better than a hierarchy if

• the taxonomy is uncertain ("Now is this a small car or a large truck?")

• there is no central authority for classification

• there is no obivous or natural order between the classes (cars can be classified by color or by size, there is no obvious rank between color and size)

• new categories may be created on the fly

Otherwise, a hierarchy gives more confidence in completeness, as every item has exactly one obviously correct location: did I find all documents about birds? Is there really no document about five-story houses?

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Tag clouds need some maintenance, I am not sure if this can be completely user-provided:

Dealing with synonyms, tag synonyms, merging tags, clarifying tags (e.g. is "blue" a feeling or a color?)

Another option are attribute-value pairs. They can be built upon a well-maintained tag cloud, e.g. grouping "red / black / blue" tags under "color". They can also work with floating values, search can be extended to similar values in case of not enough results (such as age, date, even multidimensionals like color).

However, this requires to know ahead what search criteria users need. If you need to introduce a new category, you need to re-tag the entire body of documents.

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See also my request for clarification: what are the problems? Not enough tagging? tagging to distinct? Users not finding what they are loking for? Users not confident in search results?