ACT Science vocabulary: data and graphs.

Something that deviates from what is standard, normal, or expected

The star's unusual brightness was dismissed as an anomaly until a second telescope confirmed the observation.

Memory cueOne red apple in a perfect row of green apples is an anomaly: it breaks the expected pattern.

close to an exact amount but not precise

The approximate cost of the project is two million dollars, making the degree of certainty clear from the surrounding circumstances and available evidence.

Memory cueAn approximate measurement lands near the ruler's mark, but not exactly on it.

A reference line on a graph along which values or categories are positioned.

The vertical axis displays oxygen concentration, while the horizontal axis displays elapsed time in minutes.

Memory cueAn axis is the numbered rail that gives graph points their position and meaning.

Similar in size, degree, or nature; able to be compared

No comparable study has been conducted on this scale, making the findings difficult to validate independently.

Memory cueComparable items can stand side by side on the same scale because they are sufficiently similar.

A mutual relationship or connection between two or more things, especially a statistical one

The study found a strong correlation between childhood reading habits and academic performance in college.

Memory cueCorrelation ties two changing measures together without proving one caused another.

A collection of related observations or measurements organized for analysis.

The dataset contains the temperature recorded at each depth during all twelve lake sampling trials.

Memory cueA dataset is a complete set of data points gathered into one organized container.

A lack of agreement or consistency between facts or claims

The discrepancy between the official statistics and the independent survey raised questions about data collection methods.

Memory cueA discrepancy appears when two supposedly matching facts fail to line up.

to roughly calculate or judge the value, number, or quantity of something (verb); a rough calculation or educated guess (noun).

Using the room's dimensions, Priya estimated how much paint the renovation would require, giving readers enough context to understand the word without consulting a glossary.

Memory cueAn estimate uses a lightly marked number because it is a rough calculation.

The act of extending known data or reasoning beyond what is directly observed or stated

The report's conclusions rely on an extrapolation from limited data that some experts consider overly optimistic.

Memory cueExtrapolation extends a known trend line beyond the observed data.

a thing that indicates the state or level of something

Rising unemployment is often an indicator of economic trouble, shaping how confidently the people involved could reach a defensible conclusion.

Memory cueAn indicator is the gauge needle that reveals a machine's current state or level.

To estimate a value that lies between two known data points.

Students can interpolate the likely mass at six minutes by using the recorded values at five and seven minutes.

Memory cueTo interpolate, place an estimated dot inside the gap between known dots.

The amount of separation between neighboring values, measurements, or moments.

Researchers measured the solution at a five-minute interval so the graph used evenly spaced observations.

Memory cueAn interval is the measured gap from one tick mark or observation to the next.

The middle value after a set of numbers has been arranged in order.

Because one executive earned exceptionally high pay, the median better represented the typical employee's salary.

Memory cueThe median stands on the median strip, exactly in the middle of the ordered road.

The relative size or share of a part compared to the whole

A dis proportionately large proportion of the budget was allocated to defense, leaving education and healthcare underfunded.

Memory cueProportion compares one part’s size or share with the whole.

A section or quarter (here: a region of space)

The telescope was pointed toward a quadrant of the sky where astronomers expected to find the newly predicted comet.

Memory cueA quadrant is one quarter of a circle, plane, or region.

related to quantities (numbers and amounts) rather than qualities.

The researchers collected quantitative evidence, including temperature readings and precise measurements of growth, giving readers enough context to understand the word without consulting a glossary.

Memory cueQuantitative evidence appears as measurable numbers and amounts.

amounts or numbers of something

The recipe calls for large quantities of flour and sugar, giving observers a clearer basis for judging its extent or relation to the larger whole.

Memory cueQuantities are the measured amounts written beside groups of objects.

the relative size or extent of something; a system of measurement

The disaster was on a scale never seen before, giving observers a clearer basis for judging its extent or relation to the larger whole.

Memory cueA scale compares relative size and marks measured positions along a system.

A graph of paired numerical values shown as separate points to reveal a possible relationship.

The scatterplot shows that plant height generally increases as the number of daylight hours increases.

Memory cueA scatterplot scatters paired data dots across a grid so their overall pattern becomes visible.

A measure of how widely values in a dataset spread around their average.

Two stores had equal average sales, but greater variance made one store's weekly results far less predictable.

Memory cueVariance asks how far the data dots wander away from their central camp.