1. Generalization is neccesary because people can not process so many details at one time, if you have tiny tiny details on a map alot of it wont mean anything.

2.The larger the scale the more detailed the map can be but when a map is at a small scale then things have to be generalized in ways such as using points instead of a city polygon

3.As the scale decreases the features become less detailed and more of a generalization

4.simplifacation determines the most important characters and selection makes it have fewer features and details.

5.The three types of data categorisation are nominal,ordinal and interval