Custom Metadata - Adding/Editing

Introduction

This document describes how to add and edit Custom Metadata to an acquisition, session, subject, or project. All files stored in Flywheel have corresponding metadata such as upload timestamp, file version and file type. Metadata has many useful applications in Flywheel including being used to properly categorize data, create collections or curate a data view. Custom Metadata provides more control over the metadata associate with a project, subject, session, or acquisition. Custom Metadata is indexed and searchable like any of the default metadata fields.

Note: The one exception is that the files with a leading underscore (for example:  _myfile.txt); are not indexed. 

Data Types and Descriptions

A data type must be chosen for every custom metadata field that is added. The data type controls what values can be assigned and the search operations that are available.  Searching a range of values only works for Number typed Custom Metadata.

• Array: Value is an ordered list of values - any datatype and mixed datatypes allowed

• Boolean: Value is either true or false

• Number: Value is a number

• Object: Value is a collection of key-value pairs - any datatype and mixed datatypes allowed

• String: Value is text

 Instruction Steps

Acquisition Metadata

1. Select the options menu next to the acquisition and choose Information. 
2. To edit metadata, click on the key or value. 
3. To add new metadata, click + next to Custom Information.
4. Choose a data type
5. Enter a key and value
6. Once all custom metadata has been added, click Save.
7. Navigate to the tab for the Acquisitions

The Custom Metadata is now associated with the acquisition. Create a collection, data view, or search query based on the new field. 

Subject and Session Custom Metadata

1. Navigate to the tab for the Subject or Session desired to add the Custom Metadata to. 
2. Under the Custom Information section click on the key or value to edit it.  
3. To add new metadata, click + next to Custom Information.
4. Choose a data type
5. Enter a key and value
6. Once all the custom metadata has been added, click Save. 

Subject Custom Metadata

Session Custom Metadata

The custom metadata is now associated with the subject or session. Create a collection, data view, or search query based on the new field.

Project Metadata

1. Navigate to the Information tab for the Subject or Session desired to add the custom metadata to.
2. Under the Custom Information section click on the key or value to edit it.  
3. To add new metadata, click + next to Custom Information.
4. Choose a data type
5. Enter a key and value.
6. Once all of the custom metadata has been, click Save. 

The custom metadata is now associated with the project. Create a collection, data view, or search query based on the new field.

Best Practices

Because Custom Metadata is indexed for searching and the search system is a shared resource across a Flywheel Site; it is important to use custom metadata in ways that maximize its utility and reduce the risk to performance and functionality.

• Use a consistent metadata naming and location scheme

• Do not mix datatypes for the same metadata location + name

• Objects are more searchable than Arrays

• Do not use unique identifiers, timestamps or other highly variable values for metadata key names

• Keep the system limits in mind

  • 15,000 unique fields (metadata location + name) per Flywheel Site

  • 8kb per object (project/subject/session/acquisition/file) limit for structured + custom metadata.

Resources

1. 1. Session Tab

   2. Subject Tab

   3. How to use custom project info to define custom classifications