statisticnoun
stuh-TIS-tik
A fact or piece of data expressed numerically, used to summarize or represent a broader set of information.
"The statistic that one in four adults is food-insecure comes from a national survey of 50,000 households — it isn't guesswork."
percentagenoun
per-SEN-tij
A proportion expressed as a fraction of 100, used to compare quantities regardless of their absolute size.
"A 3% rise in unemployment may sound small, but expressed as a percentage of the working population, it represents hundreds of thousands of people."
proportionnoun
pruh-POR-shun
A part considered in relation to the whole; the relative share that one quantity makes up of a total.
"The report noted that a disproportionate share of wealth — roughly 80% — is held by just 10% of the population."
margin of errornoun phrase
MAR-jin uv ER-er
The range of values within which the true result is statistically likely to fall; an expression of measurement uncertainty in polling and surveys.
"The poll gives the opposition a lead of 4 points, but with a margin of error of ±3, the race is effectively too close to call."
pollingnoun (uncountable)
POH-ling
The systematic collection of opinions from a sample of people, especially to measure public attitudes on political or social issues.
"Polling has become less reliable as fewer people answer the phone — pollsters must now correct for this in their methodology."
sample sizenoun phrase
SAM-pul syz
The number of individuals or data points included in a study or survey; a larger sample generally produces more reliable results.
"A study with a sample size of 50 cannot be reliably generalized to a population of 50 million — the number matters enormously."
mediannoun/adjective
MEE-dee-un
The middle value in an ordered dataset; more robust than the mean when data contains extreme outliers.
"The median household income is a better measure than the average — a handful of billionaires can push the mean up while the median tells you what typical families earn."
meannoun/adjective
meen
The arithmetic average of a set of values, calculated by dividing the total by the count; sensitive to extreme values.
"The mean salary in the tech sector looks impressive, but it is skewed upward by a small number of very highly paid executives."
data pointnoun phrase
DAY-tuh poynt
A single item of factual information; one observation in a larger dataset.
"One data point does not make a trend — you need to look at the pattern across many observations before drawing conclusions."
trendnoun
trend
A general direction in which data is moving over time; a pattern observable across multiple data points.
"The trend in global temperatures is unmistakable when viewed over decades, even if individual years show fluctuations."
baselinenoun
BAYS-lyn
A starting point used for comparison; the reference value against which change is measured.
"The government's 'crime is down 20%' claim only makes sense if you know the baseline — what were the numbers before the policy was introduced?"
inflationnoun (uncountable)
in-FLAY-shun
The rate at which the general level of prices rises over time, reducing the purchasing power of money.
"A 5% pay rise sounds good until you account for inflation running at 7% — in real terms, workers have taken a pay cut."
projectionnoun
pruh-JEK-shun
A forecast or estimate of a future value, based on current data and assumptions about how trends will continue.
"Projections suggest the population will reach ten billion by 2050, but projections are only as good as the assumptions embedded in them."
estimatenoun/verb
ES-tih-mut (noun) / ES-tih-mayt (verb)
An approximate calculation made with incomplete information; a figure that conveys order of magnitude rather than precision.
"The death toll is an estimate — exact counts won't be available until search and rescue operations are complete."
surveynoun/verb
SUR-vay
A systematic study that collects data from a defined group of people, typically through questionnaires or interviews.
"The survey of 10,000 workers found that 62% felt underpaid — but a self-selected online survey would not carry the same evidential weight."
methodologynoun
meth-uh-DOL-uh-jee
The system of methods and procedures used to collect, analyze, and interpret data in a study or report.
"Before trusting any statistic, ask about the methodology — how was the data collected, who was included, and how were the results analyzed?"
demographicnoun/adjective
dem-uh-GRAF-ik
A particular sector of a population, typically defined by age, income, ethnicity, or other measurable characteristics.
"The policy disproportionately affects younger demographics — those aged 18–35 will bear most of the long-term cost."
correlationnoun
kor-uh-LAY-shun
A statistical relationship between two variables — when one changes, the other tends to change in a predictable direction.
"There is a strong correlation between education levels and voter turnout, but correlation does not prove that education causes higher participation."
causationnoun (uncountable)
kaw-ZAY-shun
A direct relationship in which one event or variable directly produces another; stronger and rarer than mere correlation.
"Proving causation requires more than showing two things happen together — you need to rule out confounding variables and alternative explanations."
aggregatenoun/adjective/verb
AG-ruh-gut (noun/adj) / AG-ruh-gayt (verb)
A total formed by combining many individual elements; to collect and combine multiple data points into a single figure.
"The aggregate unemployment figure masks large regional differences — some areas have rates of 2%, while others exceed 15%."
outliernoun
OWT-ly-er
A data point that falls far outside the normal range; a result that is unusually high, low, or different from the rest of the dataset.
"The single month of 12% growth turned out to be an outlier caused by a one-time government stimulus — it did not reflect the underlying trend."
per capitaadverb/adjective (Latin)
per KAP-ih-tuh
Per person; divided by the total population, used to make fair comparisons between countries or regions of different sizes.
"China has a larger economy than Denmark in absolute terms, but Denmark's GDP per capita — the amount per person — is far higher."
adjustedadjective
uh-JUST-id
Modified to account for a distorting factor, such as inflation, seasonal variation, or population change, so that fair comparisons can be made.
"Wage growth of 4% sounds positive, but after inflation-adjusted figures are applied, real wages have actually declined."
raw datanoun phrase
raw DAY-tuh
Information in its original, unprocessed form, before any cleaning, adjusting, or analysis has been applied.
"The government released only the processed report, not the raw data — making it impossible for independent researchers to check the workings."
benchmarknoun/verb
BENCH-mark
A standard or reference point used to measure or evaluate performance, quality, or progress.
"The international benchmark for aid spending is 0.7% of gross national income — only a handful of countries consistently meet it."