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Scientific method vocabulary words

This list covers the vocabulary students need to describe and use the scientific method, from forming a hypothesis to analyzing data and drawing a conclusion. It suits science students preparing for a lab report or test, teachers building a quick reference, and anyone who wants clear language for describing how experiments work.

30 words
WordMeaningIn a sentenceSave
hypothesisnounA proposed explanation that can be tested using observations or an investigation.Our hypothesis was that the seedlings would grow taller with more light.
experimentnounA planned test used to investigate a question or test an explanation.Our experiment compared how quickly sugar dissolved in warm and cool water.
observationnounThe act of carefully watching or noticing something, or a comment based on what has been noticed.Careful observation of the birds' behavior revealed a pattern the researchers had missed.
variablenounA symbol that represents a value that may change or is not yet known.In x + 4 = 9, the variable x represents 5.
control groupnounThe group in a scientific experiment that does not receive the treatment being tested, used for comparison.Researchers gave the new drug to one group and a placebo to the control group.
datanounFacts, figures, or information collected for reference, analysis, or use in reasoning.The scientists collected years of data before publishing their findings.
conclusionnounA judgment or decision reached after considering evidence, or the final part of something.After weighing the evidence carefully, the jury reached its conclusion within a few hours.
theorynounA well-supported explanation of some aspect of the natural world, based on tested evidence.Darwin's theory of evolution reshaped how scientists understand living species.
analysisnounA detailed examination of the elements or structure of something, usually to understand or explain it.Her analysis of the sales data revealed a steady decline over three years.
evidencenounInformation or observations that help show whether a claim is true.The footprints provided evidence that an animal had crossed the garden.
procedurenounAn established series of steps followed in a particular order to complete a task or process.Employees must follow the safety procedure before operating heavy machinery.
methodnounAn organized way of doing something.Try a different method for keeping track of your notes.
measurementnounThe size, length, or amount of something as determined by measuring it.The tailor took several careful measurements before cutting into the fabric.
predictionnounA statement about what someone believes will happen in the future, based on evidence or judgment.The weather service issued a prediction of heavy snow for the weekend.
researchverbTo study a subject in detail and systematically in order to discover new facts or information.The team spent two years researching the effects of the drug before publishing results.
resultsnounThe outcomes or effects produced by an action, test, calculation, or event.The exam results will be published online early next Monday morning.
replicateverbTo make an exact copy of something, or to repeat a process and get the same result.Scientists tried to replicate the experiment's results in three separate laboratories.
samplenounA small part or quantity of something intended to show what the whole is like.The nurse took a blood sample to test for signs of infection.
trialnounA formal examination of evidence in a court of law, or a test used to check the quality or performance of something.The trial lasted three weeks before the jury reached a unanimous verdict.
qualitativeadjectiveRelating to or based on the nature or quality of something rather than a numerical measurement.The researchers conducted qualitative interviews to understand how patients felt about their treatment.
quantitativeadjectiveRelating to, measured by, or expressed as a quantity or number.The study relied on quantitative data, such as test scores and attendance rates.
constantadjectiveOccurring continuously or remaining the same without change over time.The constant noise from the construction site made it hard to concentrate.
independent variablenounIn an experiment or equation, the factor that is deliberately changed to observe its effect on another variable.In the experiment, the amount of sunlight was the independent variable, while plant height was measured.
dependent variablenounIn an experiment or equation, the variable whose value changes in response to another variable.In this experiment, plant growth is the dependent variable affected by sunlight exposure.
peer reviewnounThe evaluation of academic or professional work by others qualified in the same field before publication.The journal sent the manuscript out for peer review before deciding whether to publish it.
empiricaladjectiveBased on observation or experiment rather than theory or pure reasoning.The scientist gathered empirical evidence before drawing any conclusions.
inferencenounA conclusion reached on the basis of evidence and reasoning rather than direct statement.From the muddy footprints, the detective drew the inference that someone had entered through the garden.
correlationnounA mutual relationship or connection between two or more things, especially one where they tend to change together.Scientists found a strong correlation between exercise and improved sleep quality.
causationnounThe relationship between a cause and its effect, where one event directly brings about another.Scientists were careful to distinguish correlation from true causation in their study.
methodologynounA system of methods and principles used to carry out research or a particular activity.The thesis included a detailed methodology explaining exactly how the data was collected.

Words for the steps of an experiment

The scientific method usually starts with an observation, which leads to a question and a hypothesis, a testable guess about the answer. Researchers then design a procedure and run an experiment, carefully controlling variables so that only the independent-variable changes while the dependent-variable is measured. A control-group provides a baseline for comparison against the results.

Words for analyzing results

Once data is collected, scientists move into analysis, looking for patterns, correlation, and possible causation between variables. Words like qualitative and quantitative describe different types of data, while replicate refers to repeating a trial to confirm results are reliable. A conclusion should be based on evidence and empirical observation, not just prediction, and strong findings are usually checked through peer-review.

Frequently asked questions

What is a hypothesis in the scientific method?

A hypothesis is a testable, educated guess about the answer to a question, made before running an experiment.

What is the difference between a variable and a constant?

A variable is a factor that can change or be changed during an experiment, while a constant is kept the same throughout.