Introduction

Overview

Teaching: 17 min
Exercises: 0 min

Questions

How do I package data in a FAIR way?

How can I list the authors of individual files?

Can I use multiple licenses in the same data package?

How can I visualize JSON-LD metadata?

Objectives

Construct an RO-Crate by hand using JSON

Describe each part of the Research Object

Learn basic JSON-LD to create FAIR metadata

Connect different parts of the Research Object using identifiers

Introduction

This tutorial assumes you have already completed An overview of the RO-Crate concept and its implementations:

Key Points

RO-Crate provides a structure to make FAIR data packages

schema.org in JSON-LD provides a controlled vocabulary for FAIR metadata

Each entity of the crate is described separately

Cross-references between entities create a graph

The RO-Crate specification recommends which types and keys to use

Turning a folder into an RO-Crate

Overview

Teaching: 4 min
Exercises: 3 min

Questions

How can I start a new RO-Crate?

Objectives

Creating a skeleton RO-Crate Metadata File

Use the JSON-LD pre-amble to enable Linked Data

Turning a folder into an RO-Crate

In the simplest form, to describe some data on disk, an RO-Crate Metadata File is placed in a folder alongside a set of files or folders.

First create a new folder crate1/ and add a single file data.csv to represent our dataset:

"Date","Minimum temperature (°C)","Maximum temperature (°C)","Rainfall (mm)"
2022-02-01,16.0,28.4,0.6
2022-02-02,16.3,17.2,12.4

Next, to turn this folder into an RO-Crate we need to add the RO-Crate Metadata File, which has a fixed filename. Create the file ro-crate-metadata.json using Visual Studio Code or your favourite editor, then add the following JSON:

{
  "@context": "https://w3id.org/ro/crate/1.1/context",
  "@graph": [

  ]
}

Your folder should now look like this:

Folder listing of crate1, including data.csv and ro-crate-metadata.json

The presence of the reserved ro-crate-metadata.json filename means that crate1 (and its children) can now be considered to be an RO-Crate. We call the top-level folder of the crate for the RO-Crate Root and can now refer to its content with relative file paths.

We also need to make some declaration within the JSON file to turn it into a valid RO-Crate Metadata Document, explained in the next session.

JSON-LD preamble

The preamble of @context and @graph are JSON-LD structures that help provide global identifiers to the JSON keys and types used in the rest of the RO-Crate document. These will largely map to definitions in the schema.org vocabulary, which can be used by RO-Crate extensions to provide additional metadata beyond the RO-Crate specifications. It is this feature of JSON-LD that helps make RO-Crate extensible for many different purposes – this is explored further in the specification’s appendix on JSON-LD. In short, only JSON keys (properties) and types defined this way can be used within the RO-Crate Metadata Document.

However, in the general case it should be sufficient to follow the RO-Crate JSON examples directly without deeper JSON-LD understanding. The RO-Crate Metadata Document contains a flat list of entities as JSON objects in the @graph array. These entities are cross-referenced using @id identifiers, rather than being deeply nested. This is one major difference from JSON structures you may have experienced before. The @type keyword associates an object with a predefined type from the JSON-LD context. Almost any property can alternatively be used with an [] array to provide multiple values.

The rest of this tutorial, and indeed most of the RO-Crate specification, specify which entities can be added to the @graph array.

Key Points

Adding a RO-Crate Metadata file to a folder turns it into an RO-Crate

The RO-Crate Root is the top-level folder of the crate

RO-Crate uses schema.org as base vocabulary

The JSON-LD context enables optional Linked Data processing

Descriptions are listed flatly as entities in the @graph array

Making a metadata descriptor

Overview

Teaching: 2 min
Exercises: 2 min

Questions

Which RO-Crate version is used?

How can the crate self-identify as an RO-Crate?

Objectives

Add the first entity to the JSON-LD @graph

Indicate the version of RO-Crate

RO-Crate Metadata descriptor

The first JSON-LD entity to add has the @id value of ro-crate-metadata.json to describe the JSON file itself:

{
    "@id": "ro-crate-metadata.json",
    "@type": "CreativeWork",
    "conformsTo": {"@id": "https://w3id.org/ro/crate/1.1"},
    "about": {"@id": "./"}
}

This required entity, known as the RO-Crate Metadata Descriptor, helps this file self-identify as an RO-Crate Metadata Document, which is conforming to (conformsTo) the RO-Crate specification version 1.1. Notice that the conformsTo URL corresponds to the @context URL version-wise, but they have two different functions. The context brings the defined terms into the metadata document, while the conformance declares which RO-Crate conventions of using those terms are being followed.

RO-Crate versions

This tutorial is written for RO-Crate 1.1, the RO-Crate website will list the current specification version – RO-Crates can generally be upgraded to newer versions following semantic versioning conventions, but check the change log for any important changes. The next development version of the specification, indicated with a -DRAFT status, may still be subject to changes and should only be used with caution.

Key Points

The RO-Crate Metadata Descriptor describes the JSON-LD file itself

RO-Crate specifications are versioned

The version of RO-Crate is indicated using the conformsTo property

Declaring the root folder

Overview

Teaching: 2 min
Exercises: 1 min

Questions

What is the root folder?

Objectives

Create a top-level entity that can list the parts of the crate

RO-Crate Root

Next we’ll add another entity to the @graph array, to describe the RO-Crate Root:

{
    "@id": "./",
    "@type": "Dataset",
    "hasPart": [ 

    ]
}

By convention, in RO-Crate the @id value of ./ means that this entity describes the folder in which the RO-Crate metadata file is located. This reference from ro-crate-metadata.json is therefore semantically marking the crate1 folder as being the RO-Crate Root.

RO-Crates can be published on the Web

This example is a folder-based RO-Crate stored on disk, and therefore absolute paths are avoided, e.g. in case the root folder is moved or archived as a ZIP file.

If the crate is being served from a Web service, such as a data repository or database where files are not organized in folders, then the @id might be an absolute URI instead of ./ – this is one reason why we point to the root entity from the metadata descriptor, see section Root Data Entity for details.

Key Points

The RO-Crate Root is the top-level object of the RO-Crate

The root identifier may be a URL, but commonly just ./ for the current folder

Describing the root entity

Overview

Teaching: 4 min
Exercises: 4 min

Questions

How can I describe the crate?

How do I specify the license of the RO-Crate?

Objectives

Learn about required metadata for the RO-Crate Root

Understand license identifiers using SPDX

Describing the root entity

When describing the root entity, the properties generally apply to the whole of the crate. For instance it is a good idea to give a description of why these resources are gathered in a crate, as well as giving the crate a name and license for FAIR reuse and citation.

Add metadata to root entity

Try to add the name, description and datePublished properties, and for license as a cross-reference, use SPDX license list to find the identifier for Creative Commons Zero or another license of your choice:
Solution
{
  "@id": "./",
  "@type": "Dataset",
  "hasPart": [ ],
  "name": "Example crate",
  "description": "I created this example by following the tutorial",
  "datePublished": "2023-05-22T12:03:00+0100",
  "license": { "@id": "http://spdx.org/licenses/CC0-1.0"}  
}

License identifiers

In the above solution, the identifier for CC0-1.0 http://spdx.org/licenses/CC0-1.0 is slightly different from their listed web page URI https://spdx.org/licenses/CC0-1.0.html – the former is chosen to align with SPDX JSON-LD identifiers, which unfortunately are not shown directly on their website as permalinks. It is not a requirement in RO-Crate to use permalinks for @id of entities like licenses, it is nevertheless best practice to propagate permalinks where known.

Choosing a license

Choosing a license appropriate for your dataset can be non-trivial, particularly if third-party data/software and multiple organizations are involved. See FAIR Cookbook on licensing. It is worth noting that an RO-Crate permits data entities to have a license different from the overall Crate license. It is still recommended to choose an overall Crate license that can legally apply across all the content in the RO-Crate Root.

Key Points

Name, description, date published and license are required for the RO-Crate Root

RO-Crate allows multiple licenses for different parts

Adding cross-references

Overview

Teaching: 3 min
Exercises: 4 min

Questions

How can I describe an entity further?

How can I cross-reference different entities?

Objectives

Understand cross-references in flattened JSON-LD

Add a data entity reference from the root entity

Add another type to the root entity

About cross-references

In a RO-Crate Metadata Document, entities are cross-referenced using @id reference objects, rather than using deeply nested JSON objects. In short, this flattened JSON-LD style (shown below) allows any entity to reference any other entity, and RO-Crate consumers can directly find all the descriptions of a given entity as a single JSON object.

JSON block with id `ro-crate-metadata.json` has some attributes, `conformsTo` RO-Crate 1.2, and `about` referencing id `./`. In second JSON block with id <code>./</code> we see additional attributes such as its name and description.

Add cross-reference to data entity

Consider the root Data Entity ./, and add such a cross-reference to the file data.csv using the property called hasPart:
Solution
{
    "@id": "./",
    "@type": "Dataset",
    "hasPart": [ 
      {"@id": "data.csv"} 
    ],
    "…": "…"
}

The RO-Crate root is always typed Dataset, though @type may in some cases have additional types by using a JSON array instead of a single value. Most entities can have such more specific types, e.g. chosen from schema.org type list.

Add an additional type

Navigate the schema.org type list to find a subtype of CreativeWork that is suitable for a learning resource.

Modify the root entity’s @type to be an array.

Add the type name for learning resource at the end of the array.
Solution
{
    "@id": "./",
    "@type": ["Dataset", "LearningResource"],
    "hasPart": [ 
      {"@id": "data.csv"} 
    ],
    "…": "…"
}

The root has several metadata properties that describe the RO-Crate as a whole, considering it as a Research Object of collected resources. The section on root data entity details further the required and recommended properties of the root ./.

Key Points

The @id uniquely identifies the entity within the RO-Crate

The @id key is used for cross-referencing

Multiple types can be listed by using an array

Data entities

Overview

Teaching: 2 min
Exercises: 2 min

Questions

How do I describe the files in my RO-Crate?

Objectives

Understand the purpose of data entities

Learn required properties for data entities

Data entities

A main type of resources collected in a Research Object is data – simplifying, we can consider data as any kind of file that can be opened in other programs. These are aggregated by the Root Dataset with the hasPart property. In this example we have an array with a single value, a reference to the entity describing the file data.csv.

Referencing external resources

RO-Crates can also contain data entities that are folders and Web resources, as well as non-File data like online databases – see section on data entities.

We should now be able to follow the @id reference for the corresponding data entity JSON block for our CSV file, which we need to add to the @graph of the RO-Crate Metadata Document.

Add a data entity

Add a declaration for the CSV file as new entity with @type declared as File.

Give the file a human-readable name and description to detail it as Rainfall data for Katoomba in NSW Australia, captured February 2022.

To add this is a CSV file, declare the encodingFormat as the appropriate IANA media type string.
Solution
{
    "@id": "data.csv",
    "@type": "File",
    "name": "Rainfall Katoomba 2022-02",
    "description": "Rainfall data for Katoomba, NSW Australia February 2022",
    "encodingFormat": "text/csv"
},  

It is recommended that every entity has a human-readable name; as shown in the above example, this does not need to match the filename/identifier. The encodingFormat indicates the media file type so that consumers of the crate can open data.csv in an appropriate program, and can be particularly important for less common file extensions frequently encounted in outputs from research software and instruments.

For more information on describing files and folders, including their recommended and required attributes, see section on data entities.

Override the licence

Consider if the file content of data.csv is not covered by our overall license (CC0), but Creative Commons BY-NC-SA 4.0 (which only permits non-commercial use)

To override, add an license cross-reference property on this particular data entity
Solution
{
    "@id": "data.csv",
    "@type": "File",
    "name": "Rainfall Katoomba 2022-02",
    "description": "Rainfall data for Katoomba, NSW Australia February 2022",
    "encodingFormat": "text/csv",
    "license": { "@id": "https://creativecommons.org/licenses/by-nc-sa/4.0/" }
},  

Key Points

Data entities are files & folders within the root, as well as external Web references

Required properties for files are name and encodingFormat

License can be overridden for particular data entities

Contextual entities

Overview

Teaching: 2 min
Exercises: 2 min

Questions

How can I describe things in the world?

How can I give details about licenses?

Objectives

Understand the difference between contextual and data entities

Add a contextual entity to the RO-Crate

Contextual entities

Entities that we have added under hasPart are considered data entities, while entities only referenced from those are considered contextual entities – they help explain the crate and its content.

Adding entities to the JSON array

You may have noticed we’re adding incrementally to the @graph array. It is important to remember the , between each entity, except for the final entity in the JSON array; and likewise for the properties within the JSON object for each entity. This is an artefact of the strict JSON file format rules to simplify parsing. The order of the entities within the @graph JSON-LD array and the order of the keys within a JSON object is not significant. The graph content is given by the @id cross-references.

You may notice the subtle difference between a data entity that is conceptually part of the RO-Crate and is file-like (containing bytes), while a contextual entity is a representation of a real-life organization that can’t be downloaded: following the URL, we would only get its description. The section contextual entities explores several of the entities that can be added to the RO-Crate to provide it with a context, for instance how to link to authors and their affiliations. Simplifying slightly, a data entity is referenced from hasPart in a Dataset, while a contextual entity is referenced using any other defined property.

Detailing licenses

We have previously declared two different license cross-references. While following the URLs in this case explain the licenses well, it is also best practice to include a very brief summary of contextual entities in the RO-Crate Metadata Document. This is more important if the cross-reference do not use a permalink and may change over time. As a minimum, each referenced entity should have a @type and name property. It is also possible to add url for more information

Add licence entities

Add a contextual entity for each of the two licenses, see the licensing section for details:

Solution

{
    "@id": "https://creativecommons.org/licenses/by-nc-sa/4.0/",
    "@type": "CreativeWork",
    "name": "CC BY-NC-SA 4.0 International",
    "description": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"
},    
{
    "@id": "http://spdx.org/licenses/CC0-1.0",
    "@type": "CreativeWork",
    "name": "CC0-1.0",
    "description": "Creative Commons Zero v1.0 Universal",
    "url": "https://creativecommons.org/publicdomain/zero/1.0/"
},  

An additional exercise is to try to unify the two entites so that both use spdx identifiers, remembering to update the corresponding license cross-references when changing the @id. However, not all licenses have a direct SPDX identifier.

Key Points

Contextual entities are not considered part of the crate

Cross-references should be expanded as contextual entities

It is recommended to provide a human-readable name for licenses

Authorship in crates

Overview

Teaching: 2 min
Exercises: 4 min

Questions

How can I list who made the content of the crate?

How do I affiliate a person with their place of work?

Objectives

Adding and describing a Person contextual entity

Adding a Organization contextual entity

Understanding what it means to be an authof of the crate

Indicating the publisher of the RO-Crate

Authorship

Moving back to the RO-Crate root ./, let’s specify who are the authors of the crate.

Add an author and affiliation

Add yourself as an author of the crate using the type Person

Include your preferred name.

If you don’t have an ORCID, you may use either the URL of your main home page at your institution, or a crate-local identifier like #alice.

Include your affiliation as a string value.
Solution
{
  "@id": "./",
  "@type": "Dataset",
  "author": {"@id": "https://orcid.org/0000-0002-1825-0097"},
  "…": "…"
},
{
  "@id": "https://orcid.org/0000-0002-1825-0097",
  "@type": "Person", 
  "name": "Josiah Carberry",
  "affiliation": "Brown University"
}

Who can be authors of an RO-Crate?

When we say someone is an author of a crate, it means they have contributed something substansively to its content (typically the data). Agreement on what is considered authorship on a dataset can be tricky; you may decide some people would be better represented as contributor. One advantage of RO-Crate is that authorship can be declared explicitly also on each data entity, so it can be clearer where each person have contributed (e.g. a statistician is author of an R script). This means that generally the authors of the crate can be a broader, more inclusive list than perhaps traditionally recognized as academic authorship.

Add an organization

“Unroll” your affiliation of the person as cross-reference to another contextual entity, typed as an Organization.

You can use ROR to find an identifier for most educational/research institutions, or you can use the main web page of your organization as its @id.
Solution
{
  "@id": "https://orcid.org/0000-0002-1825-0097",
  "@type": "Person", 
  "name": "Josiah Carberry"
},
{
  "@id": "https://ror.org/05gq02987",
  "@type": "Organization",
  "name": "Brown University",
  "url": "http://www.brown.edu/"
}

The reuse of existing identifiers is important for both persons and organization from a FAIR perspective, as their names may not be globally unique.

Specify a publisher

Now imagine you are going to publish the RO-Crate on your institution’s web pages.

Cross-reference the same Organization entity with publisher from the RO-Crate Root entitity:
Solution
{
    "@id": "./",
    "@type": "Dataset",
    "publisher": {"@id": "https://ror.org/05gq02987"},
    "…": "…"
}

Key Points

Authors are described as separate entities

Organization entities can be shared by multiple persons having the same affiliation

Crate authors made (some) of the crate’s content

Publishers of an RO-Crate are typically organizations

Validating JSON-LD

Overview

Teaching: 2 min
Exercises: 4 min

Questions

How can I validate the JSON-LD?

Objectives

Learn to avoid common JSON and JSON-LD errors

Try the JSON-LD Glayground with RO-Crate metadata

Visualize the RO-Crate entities

Validating JSON-LD

As we made this RO-Crate Metadata File by hand, it’s good to check for any JSON errors, such as missing/extra , or unclosed " quotes. Try pasting the file content into the JSON-LD Playground. It should show up any errors, for example:

JSON markup - SyntaxError: JSON.parse: expected `','` or `']'` after array element 
at line 29 column 5 of the JSON data

Modify the JSON file in your editor to fix any such errors. You can also use editor commands such as Format Document to ensure you have consistent spacing, indentation and brackets.

If the document passes without errors in the JSON-LD Playground, you should see output under Expanded looking something like:

[
  {
    "@id": "ro-crate-metadata.json",
    "@type": [
      "http://schema.org/CreativeWork"
    ],
    "http://schema.org/about": [
      {
        "@id": "./"
      }
    ],
    "http://purl.org/dc/terms/conformsTo": [
      {
        "@id": "https://w3id.org/ro/crate/1.1"
      }
    ]
  },
  {
    "@id": "./",
    "@type": [
      "http://schema.org/Dataset"
    ],
    "…": "…"
  }
]

This verbose listing of the JSON-LD shows how the @context has correctly expanded the keys, but is not particularly readable. Try the Visualized tab to see an interactive rendering of the entities:

Visualized in the JSON-LD Playground

As the RO-Crate Metadata Document is valid JSON-LD it is also possible to process it using Linked Data technologies such as triple stores and SPARQL queries. It is beyond the scope of this tutorial to explain this aspect fully, but interested readers should consider how to handle relative URI references. As an example, try the Table button and notice that the entities with relative identifiers are not included. This is because when converting to RDF you need absolute URIs which do not readily exist when a crate is stored on disk, we’ve not decided where the crate is to be published yet.

Key Points

RO-Crate metadata files are valid JSON-LD

The JSON-LD Playground can do basic validation and visualization

Further use of RO-Crate as Linked Data is possible, but may require handling of relative URI references

Converting JSON-LD to triples

Overview

Teaching: 1 min
Exercises: 2 min

Questions

How can I generate RDF triples from an RO-Crate?

Objectives

Understand converting the JSON-LD to RDF triples

Learn how to create unique identifiers for items within an RO-Crate

Advanced: Converting JSON-LD to triples

Try modify the graph’s @context within the JSON-LD Playground (don’t modify the ro-crate-metadata.json on disk), and revisit the Table rendering.

{
  "@context": [
    "https://w3id.org/ro/crate/1.1/context",
    { "@base": "arcp://uuid,deffa754-c764-4e04-aabf-e600c6200553/" }
  ],
  "…": "…"
}

Triples table in the JSON-LD Playground

Above arcp://uuid,deffa754-c764-4e04-aabf-e600c6200553/ is a randomly generated identifier to represent the RO-Crate root, and now the JSON-LD Playground can show all the triples from the metadata file. You can likewise use the N-Quads button to convert the metadata file to the RDF N-Quads format. Most RDF libraries and stores have JSON-LD support, but may need to specify a base URI as we did above, making a new UUID for each imported RO-Crate.

Key Points

The JSON-LD @context maps JSON keys to schema.org vocabulary

A @base URI is needed to make absolute URIs

arcp and UUID can be used for RO-Crates that are not exposed on the Web

Visualizing a crate as HTML preview

Overview

Teaching: 3 min
Exercises: 3 min

Questions

How can an RO-Crate be rendered without showing the JSON?

How can I generate a preview of the RO-Crate?

Objectives

Explore a HTML preview of an RO-Crate

(Advanced) Try the ro-crate-html tool

HTML preview

An RO-Crate can be distributed on disk, in a packaged format such as a zip file or disk image, or placed on a static website. In any of these cases, an RO-Crate can have an accompanying HTML version (ro-crate-metadata.html) designed to be human-readable.

Example dataset for RO-Crate specification

Navigate the RO-Crate preview

Try navigating the preview of the running example and find:

What is the license of the rainfall CSV?

What is the affiliation of the crate’s author?

What does the Validity Check inspect

What is not covered by this check?

Solution

CC BY-NC-SA 4.0 International

Brown University

The context, and for root dataset: existance, valid identifier, name, description, license and date published.

The other entities were not checked, e.g. the affiliation of the author.

Advanced: Generating HTML preview

If you have Node JS installed, you can install and try the ro-crate-html tool on your crate1 folder:

npm i -g ro-crate-html
rochtml crate1/ro-crate-metadata.json

Or if you have Docker, something like:

docker pull simleo/rochtml
docker run -v $(pwd):/crate -it simleo/rochtml -c ro-crate-preview_files /crate/ro-crate-metadata.json

The above will generate a ro-crate-preview.html file within your RO-Crate Root. Experiment with modifying the Metadata file and re-generating the HTML preview to see how your rendering differs from the running example.

Key Points

RO-Crate can be rendered into a HTML preview

RO-Crate previews tend to show each entity separately

The preview HTML can be added as part of the RO-Crate

Completed RO-Crate

Overview

Teaching: 1 min
Exercises: 0 min

Questions

What should the final RO-Crate look like?

Objectives

Compare your RO-Crate with the solution

Understand the flattened nature of the JSON-LD

Complete RO-Crate Metadata Document

The final RO-Crate Metadata Document constructed in this tutorial should look something like:

`ro-crate-metadata.json`

{
  "@context": "https://w3id.org/ro/crate/1.1/context",
  "@graph": [
    {
      "@id": "ro-crate-metadata.json",
      "@type": "CreativeWork",
      "conformsTo": {"@id": "https://w3id.org/ro/crate/1.1"},
      "about": {"@id": "./"}
    },
    {
      "@id": "./",
      "@type": ["Dataset", "LearningResource"],
      "hasPart": [
        {"@id": "data.csv"}
      ],
      "name": "Example dataset for RO-Crate specification",
      "description": "Official rainfall readings for Katoomba, NSW 2022, Australia",
      "datePublished": "2023-05-22T12:03:00+0100",
      "license": {"@id": "http://spdx.org/licenses/CC0-1.0"},
      "author": { "@id": "https://orcid.org/0000-0002-1825-0097" },
      "publisher": {"@id": "https://ror.org/05gq02987"}
    },
    {
      "@id": "data.csv",
      "@type": "File",
      "name": "Rainfall Katoomba 2022-02",
      "description": "Rainfall data for Katoomba, NSW Australia February 2022",
      "encodingFormat": "text/csv",
      "license": {"@id": "https://creativecommons.org/licenses/by-nc-sa/4.0/"}
    },
    {
      "@id": "https://creativecommons.org/licenses/by-nc-sa/4.0/",
      "@type": "CreativeWork",
      "name": "CC BY-NC-SA 4.0 International",
      "description": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"
    },    
    {
      "@id": "http://spdx.org/licenses/CC0-1.0",
      "@type": "CreativeWork",
      "name": "CC0-1.0",
      "description": "Creative Commons Zero v1.0 Universal",
      "url": "https://creativecommons.org/publicdomain/zero/1.0/"
    },    
    {
      "@id": "https://orcid.org/0000-0002-1825-0097",
      "@type": "Person", 
      "name": "Josiah Carberry",
      "affiliation": {
        "@id": "https://ror.org/05gq02987"
      }
    },
    {
      "@id": "https://ror.org/05gq02987",
      "@type": "Organization",
      "name": "Brown University",
      "url": "http://www.brown.edu/"
    }
  ]
}

Key Points

A single RO-Crate lists all the entities

The order of entities in the @graph array is not important

Next steps

Overview

Teaching: 1 min
Exercises: 0 min

Questions

What else can I do with RO-Crate?

Objectives

Find additional sections in RO-Crate specification

Next steps

You have completed making a basic RO-Crate. You may try any of the following:

Add and describe additional data entities, adding additional properties for data entities
Follow the RO-Crate specification for additional contextual entities you can add to the crate
Try briefly describing provenance or software for any additional data entities you have added.

Key Points

RO-Crate specification has further details, e.g. additional contextual entities

Packaging Data using RO-Crate

Introduction

Overview

Introduction

Key Points

Turning a folder into an RO-Crate

Overview

Turning a folder into an RO-Crate

JSON-LD preamble

Key Points

Making a metadata descriptor

Overview

RO-Crate Metadata descriptor

RO-Crate versions

Key Points

Declaring the root folder

Overview

RO-Crate Root

RO-Crates can be published on the Web

Key Points

Describing the root entity

Overview

Describing the root entity

Add metadata to root entity

Solution

License identifiers

Choosing a license

Key Points

Adding cross-references

Overview

About cross-references

Add cross-reference to data entity

Solution

Add an additional type

Solution

Key Points

Data entities

Overview

Data entities

Referencing external resources

Add a data entity

Solution

Override the licence

Solution

Key Points

Contextual entities

Overview

Contextual entities

Adding entities to the JSON array

Detailing licenses

Add licence entities

Solution

Key Points

Authorship in crates

Overview

Authorship

Add an author and affiliation

Solution

Who can be authors of an RO-Crate?

Add an organization

Solution

Specify a publisher

Solution

Key Points

Validating JSON-LD

Overview

Validating JSON-LD

Key Points

Converting JSON-LD to triples

Overview

Advanced: Converting JSON-LD to triples

Key Points

Visualizing a crate as HTML preview

Overview

HTML preview

Navigate the RO-Crate preview

Solution

Advanced: Generating HTML preview

Key Points

Completed RO-Crate

`ro-crate-metadata.json`