A Gentle Introduction to Data Cleaning

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Introduction
In this section, learn about the “horror stories” of where data errors in spreadsheets have led to real consequences and how you can avoid them yourself.
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- 1.1
  Course Outline
Section 1: Nuts and chewing gum
In this section, you’ll gain practical knowledge of common formatting and layout features of spreadsheets and some ideas about how to present your raw data to others so they will love you!
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Section 2: The Invisible Man is in your spreadsheet, messing with your data
In this section, you’ll learn how even characters which you cannot see can cause havoc in data analysis. The section will teach you to ghostbust white space and other non-printable characters such as carriage returns, spaces and tabs. Once you have removed them, you can get on with your analysis in peace.
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Section 3: Your data is a witch’s brew
Three is not a number. Nor is a million. At least not when they are typed in as text in a cell in a spreadsheet. Your spreadsheet is pedantic and needs everything to be precise and consistent. Read on to learn more.
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Section 4: Did you bring the wrong suitcase (again)?
All our spreadsheet wants from us is each cell of data to be organised and neatly packed. In this section, you will analyse data to highlight problems in the way it has been structured so as to avoid them in your own work with data.
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Reading list

In the short exercise we made use of the following functions:
- The Text to Columns feature, which is extremely useful in dealing with the “wrong suitcase” issue. Here’s a decent tutorial for using this in Excel, another for Open Office (and Libre Office). It may upset you to know that Google Spreadsheet doesn’t have a straightforward Text to Columns button! However, the SPLIT function achieves the same thing, as described in this tutorial.
- The Transpose feature, which swaps rows and columns around, is neatly described for Excel in this Tech Republic tutorial, and for Open Office by Solveig Haugland on her Open Office Training blog.
The Tactical Technology Collective “Data and Design Guide” has a short chapter called Growing out of Spreadsheets, which is partly about this “wrong suitcase” issue. It looks at the difficulties of using spreadsheets when you have data that describes dynamic and complicated relationships.

Some work