Now, a pattern is an old idea. The new idea in the book was to organize implicit knowledge about how people solve recurring problems when they go about building things. W e wrote up this knowledge in the form of a pattern about entrance transitions.
Patterns are easy to remember and set out as if-then propositions.
The book gave 253 patterns about solutions that are known to work. P eople liked our book very much. We were surprised though, when we found out computer programmers liked it, because it was about building not programming. The 253 patterns are now on the website, you can browse through them, use them, think about them. They stay the same but can be combined in different ways like words in a sentence.