IDEF5

Key takeaways

IDEF5 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect IDEF5 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of IDEF5 from memory before moving on to harder problems.

Reference excerpt

IDEF5 (Integrated Definition for Ontology Description Capture Method) is a software engineering method to develop and maintain usable, accurate domain ontologies. This standard is part of the IDEF family of modeling languages in the field of software engineering.

Overview In the field of computer science ontologies are used to capture the concept and objects in a specific domain, along with associated relationships and meanings. In addition, ontology capture helps coordinate projects by standardizing terminology and creates opportunities for information reuse. The lDEF5 Ontology Capture Method has been developed to reliably construct ontologies in a way that closely reflects human understanding of the specific domain. In the IDEF5 method, an ontology is constructed by capturing the content of certain assertions about real-world objects, their properties, and their interrelationships and representing that content in an intuitive and natural form. The IDEF5 method has three main components:

A graphical language to support conceptual ontology analysis A structured text language for detailed ontology characterization, and A systematic procedure that provides guidelines for effective ontology capture.

Topics

Ontology In IDEF5 the meaning of the term ontology is characterized to include a catalog of terms used in a domain, the rules governing how those terms can be combined to make valid statements about situations in that domain, and the “sanctioned inferences” that can be made when such statements are used in that domain. In every domain, there are phenomena that the humans in that domain discriminate as (conceptual or physical) objects, associations, and situations. Through various language mechanisms, one associates definite descriptors (e.g., names, noun phrases, etc.) to those phenomena.

Central concepts of ontology The construction of ontologies for human engineered systems is the focus of the IDEF5. In the context of such systems, the nature of ontological knowledge involves several modifications to the more traditional conception. The first of these modifications has to do with the notion of a kind. Historically, a kind is an objective category of objects that are bound together by a common nature, a set of properties shared by all and only the members of the kind. While there is an attempt to divide the world at its joints in the construction of enterprise ontologies, those divisions are not determined by the natures of things in the enterprise so much as the roles those things are to play in the enterprise from some perspective or other. Because those roles might be filled in any of a number of ways by objects that differ in various ways, and because legitimate perspectives on a domain can vary widely, it is too restrictive to require that the instances of each identifiable kind in an enterprise share a common nature, let alone that the properties constituting that nature be essential to their bearers. Consequently, enterprise ontologies require a more flexible notion of kind.

Ontology development process Ontology development requires extensive iterations, discussions, reviews, and introspection. Knowledge extraction is usually a discovery process and requires considerable introspection. It requires a process that incorporates both significant expert involvement as well as the dynamics of a group effort. Given the open-ended nature of ontological analyses, it is not prudent to adopt a “cookbook” approach to ontology development. In brief, the IDEF5 ontology development process consists of the following five activities:

Organizing and Scoping: This activity involves establishing the purpose, viewpoint, and context for the ontology development project and assigning roles to the team members. Data Collection: This activity involves acquiring the raw data needed for ontology development. Data Analysis: This activity involves analyzing the data to facilitate ontology extraction. Initial Ontology Development: This activity involves developing a preliminary ontology from the acquired data. Ontology Refinement and Validation: This activity involves refining and validating the ontology to complete the development process. Although the above activities are listed sequentially, there is a significant amount of overlap and iteration between the activities.

Ontological analysis Ontological analysis is accomplished by examining the vocabulary that is used to discuss the characteristic objects and processes that compose the domain, developing rigorous definitions of the basic terms in that vocabulary, and characterizing the logical connections among those terms. The product of this analysis, an ontology, is a domain vocabulary complete with a set of precise definitions, or axioms, that constrain the meanings of the terms sufficiently to enable consistent interpretation of the data that use that vocabulary.

IDEF5 Building blocks

Definitions Some of the key terms in IDEF5 and the basic IDEF5 Schematic Language Symbols, see figure.:

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with IDEF5

Start with the simplest possible case. Write down what IDEF5 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 IDEF5 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 IDEF5 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 IDEF5

In research: IDEF5 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 IDEF5 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: IDEF5 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Data modeling, Ontology (information science), Systems analysis, so understanding it makes those chapters shorter.
In everyday life: Look for IDEF5 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.

How to study IDEF5 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what IDEF5 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 IDEF5 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is IDEF5 in simple terms?

IDEF5 (Integrated Definition for Ontology Description Capture Method) is a software engineering method to develop and maintain usable, accurate domain ontologies. This standard is part of the IDEF family of modeling languages in the field of software engineering.

Why does IDEF5 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 IDEF5?

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 IDEF5.