Terms to watch out for
pathogen: the causative agent of a communicable disease. For example, influenza (disease) is caused by influenza virus (pathogen); malaria (disease) is caused by species of Plasmodium (pathogen). It is a common mistake to use the term for the disease when you actually mean the pathogen, and vice versa
The sample was tested for measles virus not The sample was tested for measles
pathology: the study of diseases; do not use to mean disease
per cent, percentage
per cent: a term meaning units per 100
percentage: a statement of a quantity or rate expressed as the unit per cent
See also Percentages
See interval, period
principal (adjective): most important
principal (noun): a chief or head of a group (eg school principal)
principle (noun): a rule of conduct or a fundamental truth
See also hypothesis, law, theory
Proof is a dangerous word in the context of science because its common, scientific, mathematical and legal meanings are all different. This has been used to discredit scientists when they are asked, for example, to ‘prove’ evolutionary theory, that genetically modified foods can do no harm or that something else is irrefutably true. Such demands are at odds with the nature and process of science, which can disprove things that are untrue but be unable (philosophically) to prove them. Science is said to support propositions with varying degrees of probability (see significant, statistically significant), which may be so consistently high that the propositions can be relied on. Safer alternatives to proof that are often used include supported, established and demonstrated
Theories of global warming are well established in science.
Clinical trials have strongly supported the effectiveness of quinine.
Despite the above, proof and prove have technical meanings within science and technology – for example, ‘proving’ cannons to show that they are functional and the ‘proof’ of spirits of a certain strength.
proof (mathematics): a statement shown to be valid by logical argument
proof (legal): that which has been declared to be so by a jury, judge or legal authority