control variable: meaning, definition, pronunciation and examples
C1/C2Formal, Academic, Technical
Quick answer
What does “control variable” mean?
A factor in a scientific experiment that is kept constant or unchanged to isolate the effect of the independent variable on the dependent variable.
Audio
Pronunciation
Definition
Meaning and Definition
A factor in a scientific experiment that is kept constant or unchanged to isolate the effect of the independent variable on the dependent variable.
Any factor, condition, or parameter that is deliberately held steady in a study, model, or system to prevent it from influencing the outcome, thereby allowing for clearer analysis of causal relationships. In broader contexts, it can refer to a managed or regulated element within a process.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling follows regional norms ('control' not 'controll').
Connotations
Identical technical connotations in both varieties.
Frequency
Equally frequent in academic and scientific contexts in both regions.
Grammar
How to Use “control variable” in a Sentence
[Experimenter] controls for [variable] by holding [control variable] constant.The [control variable] was kept at a fixed level.A key step is to identify your [control variables].Vocabulary
Collocations
Examples
Examples of “control variable” in a Sentence
verb
British English
- The researchers controlled for prior knowledge by using a pre-test score as a covariate.
- You must control the ambient temperature during the procedure.
American English
- The analyst controlled for inflation by adjusting all monetary figures to 2020 dollars.
- The protocol requires you to control the humidity level in the lab.
adverb
British English
- This parameter is controllably adjusted via the software interface. (Rare)
- The experiment proceeded in a controlled manner.
American English
- The temperature was increased controllably over an hour. (Rare)
- The release of data was tightly controlled.
adjective
British English
- The control-group participants received a placebo.
- We need a control experiment for comparison.
American English
- She was part of the control cohort in the clinical trial.
- Run a control sample through the spectrometer first.
Usage
Meaning in Context
Business
Rare. Might be used in analytics or A/B testing contexts: 'We used customer age as a control variable in our marketing analysis.'
Academic
Core term in scientific research methods, statistics, psychology, and social sciences. 'The study included temperature as a control variable.'
Everyday
Virtually never used. The concept might be explained as 'keeping everything else the same'.
Technical
Fundamental in experimental design, engineering simulations, and econometric modelling.
Vocabulary
Synonyms of “control variable”
Strong
Neutral
Weak
Vocabulary
Antonyms of “control variable”
Watch out
Common Mistakes When Using “control variable”
- Confusing it with the independent variable (the one you change).
- Omitting necessary control variables, leading to flawed experiments.
- Using the term in non-technical contexts where it sounds jarring.
FAQ
Frequently Asked Questions
A control variable is a factor kept constant *within* all groups of an experiment. A control group is a separate group that does *not* receive the experimental treatment, used for comparison.
Conceptually similar, but a 'constant' is unchanging by nature or definition in a given context, while a 'control variable' is a factor that *could* vary but is deliberately held constant for the purposes of an experiment.
Yes, and in fact, most well-designed experiments have multiple control variables to rule out alternative explanations for the results.
It establishes internal validity. Without it, you cannot be sure that changes in the dependent variable were caused by the independent variable and not by some other, uncontrolled factor.
A factor in a scientific experiment that is kept constant or unchanged to isolate the effect of the independent variable on the dependent variable.
Control variable is usually formal, academic, technical in register.
Control variable: in British English it is pronounced /kənˈtrəʊl ˈvɛːrɪəbl/, and in American English it is pronounced /kənˈtroʊl ˈvɛriəbəl/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “Hold all else equal”
- “Ceteris paribus (Latin, used in economics)”
Learning
Memory Aids
Mnemonic
Think of a science lab CONTROLLER (control) who makes sure only one dial (variable) is turned, while all the other dials (control variables) are locked in place.
Conceptual Metaphor
SCIENTIFIC EXPERIMENT AS A PURIFICATION PROCESS (where control variables are the impurities being removed to see the pure effect).
Practice
Quiz
What is the primary purpose of a control variable?