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# System prepended metadata

title: Chapter 4. Training Data

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# Chapter 4. Training Data

## Sampling

In many cases, sampling is necessary.
 - Don't have access to all possible data.
 - Don't have much time or resource to load all data.
 - Want to do a quick experiment for a new model.

There are 2 types of sampling:
 - Nonprobability Sampling
 - Random Sampling

### Nonprobability Sampling
 