Before you can analyze data you need to clean it. Data cleaning identifies errors and corrects formatting to create consistent data. This step must be taken with extreme care and attention because without clean data the results of analysis may be false and non-reproducible.
OpenRefine 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 clean and format data effectively 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.
Data Carpentry’s teaching is hands-on, so participants are encouraged to use their own computers to ensure the proper setup of tools for an efficient workflow.
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.
This lesson requires a working copy of OpenRefine 3.4.1.
To most effectively use these materials, please make sure to install everything before working through this lesson.
If you are teaching this lesson in a workshop, please see the Instructor notes.
|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 sort and summarize our data?
How can we find and correct errors in our raw data?
|00:45||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 Numbers in OpenRefine||
How can we convert a column from one data type to another?
How can we visualize relationships among columns?
|01:25||5. Scripts from OpenRefine||
How can we document the data-cleaning steps we’ve applied to our data?
How can we apply these steps to additional data sets?
|01:40||6. Exporting and Saving Data from OpenRefine||How can we save and export our cleaned data from OpenRefine?|
|01:55||7. Other Resources in OpenRefine||What other resources are available for working with OpenRefine?|
The actual schedule may vary slightly depending on the topics and exercises chosen by the instructor.