Ways to calculate similarity

Question

I am doing a community website that requires me to calculate the similarity between any two users. Each user is described with the following attributes:

age, skin ty

Answer 1

You probably should take a look for

• Data Mining and Data Warehousing (Essential)
• Machine Learning (Extra)
• Artificial Neural Networks (Especially SOM)
• Pattern Recognition (Related)

These topics will let you your program recognize similarities and clusters in your users collection and try to adapt to them...

You can then know different hidden common groups of related users... (i.e users with green hair usually do not like watching TV..)

As an advice, try to use ready implemented tools for this feature instead of implementing it yourself...
Take a look at Open Directory Data Mining Projects