Data Cleaning with OpenRefine

A part of the data workflow is preparing the data for analysis. Some of this involves data cleaning, where errors in the data are identifed and corrected or formatting made consistent. This step must be taken with the same care and attention to reproducibility as the analysis.

OpenRefine (formerly Google Refine) is a powerful free and open source tool for working with messy data: cleaning it and transforming it from one format into another.

This lesson will teach you to use OpenRefine to effectively clean and format data and automatically track any changes that you make. Many people comment that this tool saves them literally months of work trying to make these edits by hand.

This workshop has been adapted from the Data Carpentries OpenRefine for Social Science Data lessons.

These lessons assume no prior knowledge of the skills or tools.

To get started, follow the directions in the “Setup” tab to download data to your computer and follow any installation instructions.

Prerequisites

To follow along with the workshop, you will need a working copy of OpenRefine and to download the data file from here.

To most effectively use these materials, please make sure to install everything before working through this lesson.

Schedule

Setup Download files required for the lesson
00:00 1. Introduction What is OpenRefine useful for?
00:10 2. Working with OpenRefine How can we bring our data into OpenRefine?
How can we summarize our data with facets?
How can we find and correct errors in our raw data with clustering?
How can we separate values into multiple columns?
00:40 3. Filtering and Sorting with OpenRefine How can we select only a subset of our data to work with?
How can we sort our data?
01:05 4. Examining Outliers in OpenRefine How can we see numeric outliers?
01:15 5. Using Scripts How can we document the data-cleaning steps we’ve applied to our data?
How can we apply these steps to additional data sets?
01:25 6. Exporting and Saving Data from OpenRefine How can we save and export our cleaned data from OpenRefine?
01:35 7. Other Resources in OpenRefine What other resources are available for working with OpenRefine?
01:45 Finish

The actual schedule may vary slightly depending on the topics and exercises chosen by the instructor.