computer science

Reference model

Reference model is a computer 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 Reference model rather than just read about it. In short: A reference model—in systems, enterprise, and software engineering—is an abstract framework or domain-specific ontology consisting of an interlinked set of clearly defined concepts produced by an expert or body of experts to encourage clear communication. A reference model can represent the component parts of any consistent idea, from business functions to system components, as long as it represents a complete set.

Key takeaways

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

Reference excerpt

A reference model—in systems, enterprise, and software engineering—is an abstract framework or domain-specific ontology consisting of an interlinked set of clearly defined concepts produced by an expert or body of experts to encourage clear communication. A reference model can represent the component parts of any consistent idea, from business functions to system components, as long as it represents a complete set. This frame of reference can then be used to communicate ideas clearly among members of the same community. Reference models are often illustrated as a set of concepts with some indication of the relationships between the concepts.

Overview According to OASIS (Organization for the Advancement of Structured Information Standards) a reference model is "an abstract framework for understanding significant relationships among the entities of some environment, and for the development of consistent standards or specifications supporting that environment. A reference model is based on a small number of unifying concepts and may be used as a basis for education and explaining standards to a non-specialist. A reference model is not directly tied to any standards, technologies or other concrete implementation details, but it does seek to provide a common semantics that can be used unambiguously across and between different implementations." There are a number of concepts rolled up into that of a 'reference model.' Each of these concepts is important:

Abstract: a reference model is abstract. It provides information about environments of a certain kind. A reference model describes the type or kind of entities that may occur in such an environment, not the particular entities that actually do occur in a specific environment. For example, when describing the architecture of a particular house (which is a specific environment of a certain kind), an actual exterior wall may have dimensions and materials, but the concept of a wall (type of entity) is part of the reference model. One must understand the concept of a wall in order to build a house that has walls. Entities and relationships: A reference model describes both types of entities (things that exist) and their relationships (how they connect, interact with one another, and exhibit joint properties). A list of entity types, by itself, doesn't provide enough information to serve as a reference model. Within an environment: A reference model does not attempt to describe "all things." A reference model is used to clarify "things within an environment" or a problem space. To be useful, a reference model should include a clear description of the problem that it solves, and the concerns of the stakeholders who need to see the problem get solved. Technology agnostic: A reference model's usefulness is limited if it makes assumptions about the technology or platforms in place in a particular computing environment. A reference model typically is intended to promote understanding a class of problems, not specific solutions for those problems. As such, it must assist the practitioner by aiding the process of imagining and evaluating a variety of potential solutions. That does not preclude the development of a reference model that describes a set of software applications, because the problem space may be "how to manage a set of software applications."

The uses of a reference model There are many uses for a reference model. One use is to create standards for both the objects that inhabit the model and their relationships to one another. By creating standards, the work of engineers and developers who need to create objects that behave according to the standard is made easier. Software can be written that meets a standard. When done well, a standard can make use of design patterns that support key qualities of software, such as the ability to extend the software in an inexpensive way. Another use of a reference model is to educate. Using a reference model, leaders in software development can help break down a large problem space into smaller problems that can be understood, tackled, and refined. Developers who are new to a particular set of problems can quickly learn what the different problems are, and can focus on the problems that they are being asked to solve, while trusting that other areas are well understood and rigorously constructed. The level of trust is important to allow software developers to efficiently focus on their work. A third use of a reference model is to improve communication between people. A reference model breaks up a problem into entities, or "things that exist all by themselves." This is often an explicit recognition of concepts that many people already share, but when created in an explicit manner, a reference model is useful by defining how these concepts differ from, and relate to, one another. This improves communication between individuals involved in using these concepts. A fourth use of a reference model is to create clear roles and responsibilities. By creating a model of entities and their relationships, an organization can dedicate specific individuals or teams, making them responsible for solving a problem that concerns a specific set of entities. For example, if a reference model describes a set of business measurements needed to create a balanced scorecard, then each measurement can be assigned to a specific business leader. That allows a senior manager to hold each of their team members responsible for producing high quality results. A fifth use of a reference model is to allow the comparison of different things. By breaking up a problem space into basic concepts, a reference model can be used to examine two different solutions to that problem. In doing so, the component parts of a solution can be discussed in relation to one another. For example, if a reference model describes computer systems that help track contacts between a business and their customers, then a reference model can be used by a business to decide which of five different software products to purchase, based on their needs. A reference model, in this example, could be used to compare how well each of the candidate solutions can be configured to meet the needs of a particular business process.

Examples Instances of reference models include, among others:

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Reference model

Start with the simplest possible case. Write down what Reference model claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer 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 Reference model 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 Reference model 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 Reference model

In research: Reference model appears in computer 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 Reference model 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: Reference model is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer architecture, Reference models, Software engineering terminology, so understanding it makes those chapters shorter.
In everyday life: Look for Reference model 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 Reference model in 20 minutes

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

Frequently asked questions

What is Reference model in simple terms?

Why does Reference model matter?

Because it connects several computer 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 Reference model?

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 Reference model.