science

Lexical diversity

Lexical diversity 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 Lexical diversity rather than just read about it. In short: Lexical diversity is one aspect of 'lexical richness' and refers to the ratio of different unique word stems (types) to the total number of words (tokens). The term is used in applied linguistics and is quantitatively calculated using numerous different measures including Type-Token Ratio (TTR), vocd, and the measure of textual lexical diversity (MTLD).

Key takeaways

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

Reference excerpt

Lexical diversity is one aspect of 'lexical richness' and refers to the ratio of different unique word stems (types) to the total number of words (tokens). The term is used in applied linguistics and is quantitatively calculated using numerous different measures including Type-Token Ratio (TTR), vocd, and the measure of textual lexical diversity (MTLD). A common problem with lexical diversity measures, especially TTR, is that text samples containing a large number of tokens give lower values for TTR since it is often necessary for the writer or speaker to re-use many words. One consequence of this is that it is often assumed that lexical diversity can only be used to compare texts of the same length. Yet, many measures of lexical diversity attempt to account for sensitivity to text length. Surveys of such measures are provided by Baayen and more recently Bestgen.

Definitions In a 2013 article Scott Jarvis proposed that lexical diversity, similar to diversity in ecology, is a perceptual phenomenon. Lexical redundancy is a positive counterpart of lexical diversity in the same way as lexical variability is the mirror image of repetition. According to Jarvis's model, lexical diversity includes variability, volume, evenness, rarity, dispersion and disparity. According to Jarvis, the six properties of lexical diversity should be measured by the following indices.

References

Worked examples

Example 1 — a first encounter with Lexical diversity

Start with the simplest possible case. Write down what Lexical diversity 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 Lexical diversity 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 Lexical diversity 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 Lexical diversity

In research: Lexical diversity 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 Lexical diversity 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: Lexical diversity is common in secondary-school and first-year university syllabi. It links to neighbouring topics Linguistics, so understanding it makes those chapters shorter.
In everyday life: Look for Lexical diversity 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Lexical diversity” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Lexical diversity in 20 minutes

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

Frequently asked questions

What is Lexical diversity in simple terms?

Why does Lexical diversity 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 Lexical diversity?

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 Lexical diversity.