science

Obligatory contour principle

Obligatory contour principle 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 Obligatory contour principle rather than just read about it. In short: The obligatory contour principle (OCP) is a hypothesis in autosegmental phonology that states that (certain) consecutive identical features are banned in underlying representations. The OCP is most frequently cited when discussing the tones of tonal languages (stating for example that the same morpheme may not have two underlying high tones), but it has also been applied to other aspects of phonology.

Key takeaways

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

Reference excerpt

The obligatory contour principle (OCP) is a hypothesis in autosegmental phonology that states that (certain) consecutive identical features are banned in underlying representations. The OCP is most frequently cited when discussing the tones of tonal languages (stating for example that the same morpheme may not have two underlying high tones), but it has also been applied to other aspects of phonology. The principle is part of the larger notion of horror aequi, that language users generally avoid repetition of identical linguistic structures.

Background considerations A commonly held conception within phonology is that no morpheme is allowed to contain two consecutive high tones. If two consecutive high tones appear within a single morpheme, then some rule must have applied (Odden 1986). Maybe one of the surface high-tone vowels was underlyingly high-toned, while the other was underlyingly toneless. Then, since all vowels must have tone at the surface (in this hypothetical language), the high tone of the one vowel spreads onto the other. Alternatively, one (or both) of the vowels may have started out low-toned and become high-toned due to the application of some rule; or perhaps there was a low tone between the two high tones that got deleted at some point. Regardless, the OCP claims that there can not have been two consecutive high tones (nor two consecutive low tones, etc.) in the underlying representation of the morpheme, i.e. in the morpheme's lexical entry.

History The locus classicus of the OCP is Leben (1973), in which it was formulated as a morpheme-structure constraint precluding sequences of identical tones from underlying representations. In autosegmental phonology (Goldsmith 1976), with articulated conceptions about associations between featural melodies and skeletal units (i.e. CV phonology, see McCarthy 1979, McCarthy 1981, Steriade 1982, Clements & Keyser 1983), moraic phonology (Hyman 1985, Hayes 1989), the OCP was considered to be relevant to adjacent singly linked melodies but not to doubly linked melodies. The OCP in this "rules and constraints" era was no longer simply a constraint on underlying forms, but also began to play a role in the course of a phonological derivation. McCarthy (1986) proposed that the OCP can actively block the application of or repair the output of phonological rules, while in Yip (1988), Moira Yip attempted to extend the role of the OCP to trigger the application of rules as well. However, there was also a strong opposition to the OCP as a formal constraint in phonological theory, headed by David Odden. Odden (1986) showed that, contrary to the contemporaneous assumption that constraints were inviolable, an examination of African tonal systems reveals many apparent surface violations of the OCP. A lively debate continued between John McCarthy and Odden for several years, with each adding an extra "anti-" to the title of the previous article of the other - e.g. "Anti anti-gemination and the OCP" (Odden 1988), a reply to (McCarthy 1986).

Debate In optimality theory (OT) (Prince & Smolensky 2004), the OCP has been again redefined as a violable constraint. Yet many issues as to its precise formal character remain: locality - what is the domain of the OCP (i.e. strict adjacency, etc.) and how is the domain represented in the theory; near-identical sequences - many languages show an OCP-like resistance to sequences of segments that differ in just one distinctive feature; there is a question of this being the effect of the OCP, or possibly some other constraint. If the latter, then there is the question of how this constraint formally relates to the OCP; status as an OT constraint - if the OCP is a single constraint, or the local self-conjunction of markedness constraints (Alderete 1997). These and other issues related to the OCP continue to be debated in phonological theory.

Meeussen's rule

A particular instance of the OCP is Meeussen's rule (Goldsmith 1984), named after the Belgian Bantu specialist A. E. Meeussen, which has been used to explain how a sequence HH tones becomes HL in various Bantu languages.

References

External links

Worked examples

Example 1 — a first encounter with Obligatory contour principle

Start with the simplest possible case. Write down what Obligatory contour principle 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 Obligatory contour principle 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 Obligatory contour principle 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 Obligatory contour principle

In research: Obligatory contour principle 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 Obligatory contour principle 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: Obligatory contour principle is common in secondary-school and first-year university syllabi. It links to neighbouring topics Phonology, so understanding it makes those chapters shorter.
In everyday life: Look for Obligatory contour principle 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 Obligatory contour principle in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Obligatory contour principle 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.
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Frequently asked questions

What is Obligatory contour principle in simple terms?

Why does Obligatory contour principle 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 Obligatory contour principle?

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 Obligatory contour principle.