Is the 'first quartile' the best or the worst?

It is the lowest. The first quartile (Q1) is the 25th percentile, meaning 25% of the data is below it. The 'top quartile' or 'fourth quartile' is the best.

What is the difference between a quartile and a percentile?

Quartiles are specific percentiles. Q1 is the 25th percentile, Q2 is the 50th percentile (the median), and Q3 is the 75th percentile. Percentiles can be any value (e.g., 10th, 95th).

Can 'quartile' be used as an adjective?

Yes, though less common. For example, 'quartile distribution' or 'quartile ranking' are acceptable. Its primary part of speech is a noun.

How do I pronounce 'quartile' correctly?

Stress the first syllable: KWOR-tyle. The 'i' is long, as in 'mile'. The main UK/US difference is the vowel in the first syllable: /ɔː/ in UK vs. /ɔːr/ in US.

quartile

UK/ˈkwɔː.taɪl/US/ˈkwɔːr.taɪl/

Academic, Technical, Business

My Flashcards

Definition

Meaning

A statistical term for each of four equal groups into which a population or data set can be divided, based on their rank or distribution.

The value that marks the boundary between each quarter of the data; can refer to the group itself (e.g., 'the top quartile') or the cut-off point (e.g., 'the first quartile is 15').

Linguistics

Semantic Notes

Often used in contexts like test scores, income distribution, performance metrics, and statistical analysis. Implies a ranking or distribution system.

Dialectal Variation

British vs American Usage

Differences

No significant differences in meaning. Spelling and usage are identical.

Connotations

Neutral statistical term in both variants.

Frequency

Slightly more frequent in American business and academic writing due to widespread use of standardized testing and data analytics.

Vocabulary

Collocations

strong

first quartilethird quartileupper quartilelower quartiletop quartilebottom quartileinterquartile range

medium

quartile rankquartile divisionfall into a quartilecalculate the quartilequartile boundary

weak

quartile scorequartile dataquartile analysisquartile groupquartile measure

Grammar

Valency Patterns

[be] in the [first/second/third/fourth] quartile[calculate/find/determine] the [first] quartile[score/rank] in the [top/bottom] quartile[divide/separate] into quartiles

Vocabulary

Synonyms

Strong

percentile (specific type)quantile (broader category)

Neutral

quartersegmentdivision

Weak

groupbrackettier

Vocabulary

Antonyms

wholetotalaggregatemeanaverage (as a central measure, not a division)

Phrases

Idioms & Phrases

“[be] in the wrong quartile (humorous, implying underperformance)”
“quartile jump (significant improvement in ranking)”

Usage

Context Usage

Business

Used in reports to segment performance, sales figures, or customer value. E.g., 'Our profitability is in the top quartile for the industry.'

Academic

Common in statistics, social sciences, and education research to describe distributions. E.g., 'Participants in the lowest quartile for income showed different outcomes.'

Everyday

Rare in casual conversation. Might appear in discussions about school test results, such as league tables.

Technical

A precise term in statistics. The first quartile (Q1) is the 25th percentile, the second (Q2) is the median, and the third (Q3) is the 75th percentile.

Examples

By Part of Speech

noun

British English

Her score placed her in the upper quartile of all applicants.
The interquartile range is a useful measure of statistical dispersion.
We need to analyse the performance by quartile.

American English

The company ranks in the top quartile for customer satisfaction.
The first quartile for the data set was surprisingly low.
Students were grouped into quartiles based on their pre-test scores.

Examples

By CEFR Level

The school's results are in the top quartile nationally.
His salary is in the third quartile for his age group.

The report showed our department's efficiency had moved from the third to the second quartile.
To find outliers, look at data points below the first quartile or above the third quartile.

The interquartile range, between Q1 and Q3, provides a robust view of the data's spread, mitigating the effect of extreme values.
A quartile-quantile (Q-Q) plot is used to compare two probability distributions.

Learning

Memory Aids

Mnemonic

Think of a 'QUARTER' of a mile race – a 'quartile' divides data into four QUARTERS.

Conceptual Metaphor

DIVISION AS RANKING (data is a line of people sorted by height; quartiles mark where to cut the line into four equal groups).

Watch out

Common Pitfalls

Translation Traps (for Russian speakers)

False friend with 'квартал' (which means 'city district' or 'quarter of a year', not a statistical division). The correct Russian statistical term is 'квартиль'.

Common Mistakes

Confusing 'quartile' with 'quarter' as a time period.
Using 'quartile' to mean simply '25%' rather than the boundary marking 25%.
Miscalculating quartiles (e.g., Q1 is the median of the lower half, not simply the 25th data point).
Saying 'first quartile' to mean the best group (it is actually the lowest 25%).

Practice

Quiz

Fill in the gap

The range is calculated as Q3 minus Q1 and shows where the middle 50% of the data lies.

Multiple Choice

If a student's score is at the 80th percentile, which quartile are they in?

FAQ

Frequently Asked Questions

: It is the lowest. The first quartile (Q1) is the 25th percentile, meaning 25% of the data is below it. The 'top quartile' or 'fourth quartile' is the best.
: Quartiles are specific percentiles. Q1 is the 25th percentile, Q2 is the 50th percentile (the median), and Q3 is the 75th percentile. Percentiles can be any value (e.g., 10th, 95th).
: Yes, though less common. For example, 'quartile distribution' or 'quartile ranking' are acceptable. Its primary part of speech is a noun.
: Stress the first syllable: KWOR-tyle. The 'i' is long, as in 'mile'. The main UK/US difference is the vowel in the first syllable: /ɔː/ in UK vs. /ɔːr/ in US.