science

OWL-S

OWL-S is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand OWL-S rather than just read about it. In short: OWL-S is an ontology built on top of Web Ontology Language (OWL) by the DARPA DAML program. It replaces the former DAML-S ontology. "OWL-S is an ontology, within the OWL-based framework of the Semantic Web, for describing Semantic Web Services.

Key takeaways

OWL-S belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect OWL-S to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of OWL-S from memory before moving on to harder problems.

Reference excerpt

OWL-S is an ontology built on top of Web Ontology Language (OWL) by the DARPA DAML program.

It replaces the former DAML-S ontology. "OWL-S is an ontology, within the OWL-based framework of the Semantic Web, for describing Semantic Web Services. It will enable users and software agents to automatically discover, invoke, compose, and monitor Web resources offering services, under specified constraints."

The OWL-S Ontology

Development of OWL-S aims to enable the following tasks:

Automatic Web service discovery: with the development of the Semantic Web, many Web Services will be available on the Web, performing the most various tasks. OWL-S will help software agents to discover the Web Service that would fulfill a specific need within some quality constraints, without the need for human intervention. Automatic Web service invocation: generally, it is necessary to write a specific program to invoke a Web Service, using its WSDL description. OWL-S will open the possibility for a software agent to automatically read the description of the Web Service's inputs and outputs and invoke the service. Automatic Web service composition and interoperation: in a Web where many services are available, it should be possible to perform a complex task, involving the coordinated invocation of various Web Services, based solely on the high-level description of the objective. OWL-S will help in the composition and interoperation of the Services in a way that will enable the automatic execution of this tasks. The OWL-S ontology has three main parts: the service profile, the process model and the grounding.

The service profile is used to describe what the service does. This information is primary meant for human reading, and includes the service name and description, limitations on applicability and quality of service, publisher and contact information. The process model describes how a client can interact with the service. This description includes the sets of inputs, outputs, pre-conditions and results of the service execution. The service grounding specifies the details that a client needs to interact with the service, as communication protocols, message formats, port numbers, etc.

OWL-S and WSDL OWL-S requires an additional description for a full specification of the grounding, the most commonly used being WSDL. Although both languages target at different levels of specification, there is an intersection between them:

An OWL-S atomic process corresponds to a WSDL operation; The inputs and outputs of an OWL-S atomic process correspond to WSDL messages; The types of the inputs and outputs of an OWL-S atomic process correspond to WSDL abstract types.

See also Ontology (information science) Semantic Web Semantic Web Services Web Ontology Language (OWL) WSDL WSMO

References

Worked examples

Example 1 — a first encounter with OWL-S

Start with the simplest possible case. Write down what OWL-S claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to OWL-S before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about OWL-S ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of OWL-S

In research: OWL-S appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses OWL-S in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: OWL-S is common in secondary-school and first-year university syllabi. It links to neighbouring topics Markup languages, Semantic Web, Web services, so understanding it makes those chapters shorter.
In everyday life: Look for OWL-S outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study OWL-S in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what OWL-S means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain OWL-S out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is OWL-S in simple terms?

OWL-S is an ontology built on top of Web Ontology Language (OWL) by the DARPA DAML program. It replaces the former DAML-S ontology. "OWL-S is an ontology, within the OWL-based framework of the Semantic Web, for describing Semantic Web Services.

Why does OWL-S matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study OWL-S?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on OWL-S.