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Getting Started with Data Cleaning and OpenRefine

This guide is meant to introduce readers to the importance of data cleaning through a useful tool for working with "messy" data, OpenRefine.


GREL, or Google Refine Expression Language, is a language used to work with and manipulate data, cells, and columns in OpenRefine.

GREL can be utilized in a number of places in OpenRefine including:

  1. Adding a column based on another column
  2. Adding a column by fetching URLs
  3. Transforming cell contents
  4. Creating custom facets (both number and text)


NOTE: GREL is case-sensitive, meaning that (for example) "Match" and "match" will not produce the same result.

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