Receptor — a receiver in a cell
It helps a cell receive a signal. A suitable substance can activate it and trigger a response in the cell. [3]
Placebo — a comparison preparation
It does not contain the study ingredient. It is given to some participants to compare their results with those receiving the substance being studied. [5]
Clinical trial — a study involving people
It tests whether treatment helps and what problems it may cause. Research proceeds in stages. Even a large study does not yet mean permission to sell a medicine. [5]
Randomisation — allocation by chance
Chance determines which group each person enters. This helps make comparisons fairer. [5]
Biomarker — an indicator of what is happening in the body
Something that can be measured, such as a substance in the blood. It may help assess a disease or response to treatment. A better result does not always mean a person feels better. [4]
Why are different results reported from the same study?
Not everyone finishes a study or takes the medicine throughout. Researchers must decide how to account for these situations. Different methods of calculation can produce different numbers.
What is this called in scientific papers?
You may encounter the word estimand. It specifies exactly which effect an analysis aims to calculate and how it handles situations such as treatment discontinuation.
Where does this information come from?
Show sources and how they were checked
- NCI: Receptor
Scientific glossary · full definition reviewed. Accessed: 2 November 2026.
- NIH / NEI: Learn About Clinical Trials
Public institution guide · full page. Accessed: 2 November 2026.
- NCI: Biomarker
Scientific glossary · full definition reviewed. Accessed: 2 November 2026.