In a perfect world, we wouldn't even need to have this chapter. In a perfect world, we would have perfect, clean data that we could easily analyze in Tableau. But, alas, in reality, the data that we need to use will most likely need to be cleaned, transformed, and managed before we can effectively use it in Tableau.

There are tools that exclusively help clean and re-shape data. Many refer to these as ETL (Extract, Transform, and Load) tools. While Tableau is not an ETL tool, it has the ability to help clean or prepare data if it is not possible to clean or prepare it at the data source. Calculated fields, discussed in Appendix A, Calculated Fields Primer, are also invaluable in the data cleaning process.