Science Vocabulary/Words that mean different things in science contexts

Abstract: A short summary of key information, usually including the main results of an experiment and their greater implications. Not something that is purely conceptual or theoretical (e.g. NOT: an artistic impression).

Chemical: Technically, any matter (such as water) is a chemical, but most people refer to chemicals as substances that are the same in structure throughout. Not necessarily harmful or toxic in some way.

Control: In an experimental setting, a control group is the group of individuals whose response is compared against those for which variables have been altered. Controls are therefore vital to provide baseline data, and to allow researchers to compare data with when looking to provide evidence that one or more variables cause a measurable effect. Not the group that is manipulated, or the subjects whose exposure to changed variables is somehow controlled (e.g. Not: the group that is given a set dosage of a pill, but the group that is given no pill).

De-Extinction: Creating an organism or species that is extinct via cloning or some other artificial means (e.g. selective breeding of a closely related species to favour traits associated with the target species). Note that this can theoretically apply to organisms that went extinct yesterday, or millions of years ago. Not organisms that have been seen after they were believed to have gone extinct (e.g. NOT: the coelacanth fish).

Dependent/Independent: Dependent variables are those that are purposefully manipulated in an experiment (e.g. food types offered to pet dogs), whereas independent variables are not changed (e.g. the age of the dogs being studied). To help you remember the right definition, think of dependent variables as depending on the researcher to change them.

Experiment: The procedure followed to test the effect of one or more variables on each other. The key thing to remember is that for this procedure to be called an experiment it must be repeatable. This is important because similar results must be replicated a number of times to support the initial findings (and to refute the chance that they occurred randomly). Not simply trying things out, in the way that you might experiment with different titles before settling on the best one for your essay.

Hypothesis: A hypothesis must actually be testable by an experiment (e.g. I hypothesize that doubling the dose of drug A will improve the speed at which patients recover from infection). Not simply an idea or belief (e.g. NOT: I hypothesize that we will have a cure for Alzheimer’s disease in the next five years).

Invasive: Can either be used to 1) refer to organisms that are historically not native to an area or environment, and which spread rapidly, often wiping out biodiversity, or 2) rapidly spreading and harmful (e.g. viruses, cancers).

Law: An explanation of phenomena that has been repeatedly and consistently backed up by experimental evidence over a long period of time. Because it will always apply under given circumstances, there must be a direct causational rule that governs the way variables interact. Not an explanation that is unchangeable (they often do as knowledge accrues over time).

Mutation: A change in a sequence of DNA. This may have negative, neutral or positive effects, but it occurs randomly, and very commonly in all organisms. Not only applicable when a change has negative consequences, and not only referring to such a change that occurs as a result of an unnatural cause (such as exposure to excess radiation).

Natural: This word can mean different things even within scientific circles. Historically, it means something that has not been created by mankind, but it can also mean something grown/bred without any intervention (e.g. without genetic modification). It has other uses, too (such as in referring to a species that has been present for a very long time in a given environment). Be sure to define this word if/when you need to use it. Not simply referring to a process that occurs under normal circumstances.

Organic/Inorganic: 1) An organic molecule/compound contains the element carbon (C) whereas 2) an inorganic compound generally does not. Molecules like DNA and methane that are associated with organisms are organic. Not referring to something that happens 1) under normal circumstances (e.g. NOT: My love for science evolved organically) or 2) otherwise

Poisonous/Venomous: These two words are often used interchangeably but there is a subtle difference: venomous organisms inject poison via fangs or some other device (e.g. snakes) whereas poisonous organisms may pass on their poison without injecting it (e.g. frogs).

Positive Feedback: A cycle in which things spiral more and more. An effect is increased by its own influence (e.g. Nervousness before an exam makes you sleep badly, which makes you more nervous, which makes you sleep even worse...). Note that positive feedback cycles are not necessarily good things (they’re often bad).

Proof: Science accrues evidence, and knowledge, over time to help construct theories and laws, but these are never final and are open to change. As a result, proofs, like those that exist in logic and mathematics, do not exist in science. Similarly, when conducting experiments, you may gather data that supports a hypothesis, but this is not the same as providing a proof. Not to be used to describe results that support an interpretation.

Theory: An explanation of phenomena that has become accepted in the scientific community, but which is like a basket of knowledge that grows and adapts over time as the basket fills. Note that there is a significant body of work behind a theory. Not simply a guess or hunch, which is how non-scientists sometimes interpret the word (e.g. NOT: I have a theory that walking dogs before exams leads to better performance in exams).

Variable: Changing quantities of something being measured (usually very specifically). These could be characteristics, types, or measurements. For example, an experimenter might wish to alter temperature and animal weight when assessing whether those variables affect the amount of time pet mice spend sleeping in a 24-hour period. Not used to casually describe change (e.g. NOT: the weather was variable today).

Volume: Scientists typically use volume to describe the three-dimensional measure of something (solid, liquid or gas). Generally not a description of how loud a sound is.