Final answer:
The effective number of types takes into account the number of distinct categories in a given context, considering that not all categories are equally represented.
Step-by-step explanation:
The effective number of types refers to the concept of the number of distinct types or categories present in a given context. It takes into account the fact that there may be multiple ways to classify or categorize something, and not all categories are equally represented. For example, if there are 300,000 types of beetles in the world, but you can only name a few, it shows that the effective number of types is much smaller than the total number. In this case, the effective number of types would be the number of beetle types that are known and recognized by people.