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But with so many patterns, how do we choose a pattern? So

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this is a possible approach that you can follow. First of all, you

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want to make sure that you understand your design context. You understand

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what you're designing and what are the issues involved with this design. What

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are the problems that you need to solve. At this point, you

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can examine the patterns catalog, or,if

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you're already familiar with the catalog, just

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think about the possible patterns that you could use. Once you identify

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the patterns that you can use, you also want to study them and

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study the related patterns. So normally if you look at any pattern catalog,

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for each pattern there will also be a list of related patterns. So

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you can also look at those to see whether maybe some of those

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might be more applicable. And finally, once you identify the pattern that you

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think is appropriate, you will apply that pattern. When you do that, just

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be mindful that there are pitfalls in the use of patterns. One obvious

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one is the fact that you might select the wrong pattern and make

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your design worse instead of better. The second one is that if you

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get too excited about patterns, then you

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might be abusing patterns, so just using too

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many patterns, and end up with a design

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that is more complicated rather than less complicated.

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So always be careful, spend the time to figure out which one is the right

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pattern to apply, and make sure that you

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don't use patterns that you don't actually need.