Hi and welcome to a new episode of Solid in Short.

In this episode I will continue to talk about Solid from an organisational point of view and delve deeper into the scope of the use cases in which Solid can be used and the potential roles that an organisation can take depending on this scope.

Use cases for the Solid standard in organisations typically differ in the way they span over systems that exchange personal data within or across organisation borders. When the standard is used internally, the scope of the use cases is the organisation itself and the ecosystem is said to be an internal one. Examples of cases in which Solid can be used internally is to improve interoperability between subsidiaries or systems. When the standard is used across the border of the organisation, the use cases have an external scope and the ecosystem is said to be an external one.

In an external Solid ecosystem, organisations can take up several roles, depending on how they want to position themselves. Organisations can be data producers, data consumers and or data custodian. These roles are not mutually exclusive.

Data exchange in an external ecosystem is also different from data exchange in an internal ecosystem. That is, when data flows across organisational boundaries, it is the user that is in control. Therefore, in the case of external data exchange, it is better to talk about data reuse.

This also means that data producers, in fact, enable their users to reuse their data at another party and that data consumers enable their users to reuse their data from another party at their organisation.

The role of a data custodian in an external Solid ecosystem entails that the organisation takes care of the storage and management of the data. In concrete terms, this means that the organisation becomes a ‘pod provider’.

When two organisations decide to let their users exchange data, that is, one organisation becomes a data producer and the other a data consumer, they need a data custodian. For this, there are generally two options. The first option is that the organisations agree to let their users choose an independent data custodian or pod provider. However, in the short term this option might cause a practical problem: currently, there are not many independent pod providers. Luckily there is also a second option: the data producer also takes the role of data custodian. In this case, the data custodian and producer may also choose to curate the list of data consumers and decide to make the contents of the pods read-only. The interactions between data producer, consumer and custodian, together with parameters about the curation of consumers and access rights are typically called the ‘pod architecture’.

Note that the data producer may take up the data custodian role temporarily. Because Solid is a standard meant to make data stores and apps interoperable, the data producer can always decide to use an external party as a custodian for the data.

Based on these considerations, you can see that Solid has the potential to be used for both internal and external standardisation so it can function as a way to construct a widely supported standardised personal data infrastructure. In addition, because interoperability is guaranteed, consortia for external use cases can decide on roles without having to worry about the long-term implications of pod architecture.

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