Synonyms—not!
Which sentences are correct?
- Plants grow in dirt.
- Plants grow in soil.
- Accurate directions can be incorrect.
- Precise directions can be incorrect.
- Today’s climate is cloudy with a chance of rain.
- Today’s weather is cloudy with a chance of rain.
- Your mass is the same on Earth and the Moon.
- Your weight is the same on Earth and the Moon.
- “Pets reduce stress” is an interesting hypothesis.
- “Pets reduce stress” is an interesting theory.
The correct sentences are B, D, F, G, and I.
Why?
Soil is a dynamic ecosystem made up of organic matter (e.g., fallen leaves), water, air, minerals, and living organisms. Dirt includes no organic matter and doesn’t support life. Dirt is dead soil.
Accuracy refers to correctness, while precision refers to exactness. An accurate result is correct. A precise result is consistent and repeatable. For example, your bathroom scale may consistently register three pounds more than your actual weight. The measurement is not accurate—but it is precise. Precision in language refers to highly exact wording that is not necessarily truthful (i.e., accurate).
Weather is the day-to-day, local conditions of the atmosphere. Climate is the long-term weather pattern of a region. For example, “a rainy afternoon” refers to the weather, while “wet winters” refers to the climate.
Mass is a measure of the amount of matter that makes up an object. Weight is a measure of the force of gravity acting on that matter. You weigh more on Earth than on the Moon due to differences in gravity. But your mass remains the same.
In everyday usage, a hypothesis is an educated guess. In scientific contexts, a hypothesis is a testable statement based on observed phenomena. For example, salt lowers the freezing point of water.
In everyday terms, a theory is an unproven assumption. It feels less academic than the casual meaning of hypothesis, which still sounds formal. But in scientific terms, the opposite is true. A theory is an established explanation rigorously tested and supported by substantial evidence that ties together many observations and hypotheses. For example, evolution is a scientific theory.
A theory is one of the strongest forms of scientific explanation. So the argument that evolution is just a theory misapplies the everyday meaning of theory in a scientific context. A scientific theory is never mere conjecture.
Double-check your intended meaning when using these terms. Neither term in each confused pair is interchangeable with the other. Each has its own distinct meaning and usage. Choose carefully.
