Glossary term	Definition
conclusion	A judgement based on evidence.
controlled variable	A variable that is kept constant (or changed in constant ways) during an investigation.
dependent variable	A variable that changes in response to changes to the independent variable in an investigation.
digital technologies	Systems that handle digital data, including hardware and software, for specific purposes.
enthalpy	A thermodynamic quantity equivalent to the total heat content of a system.
entropy	The degree of disorder or randomness in the system.
environment	All surroundings, both living and non-living.
hypothesis	A tentative explanation for an observed phenomenon, expressed as a precise and unambiguous statement that can be supported or refuted by investigation.
independent variable	A variable that is changed in an investigation to see what effect it has on the dependent variable.
investigation	A scientific process of answering a question, exploring an idea or solving a problem, which requires activities such as planning a course of action, collecting data, interpreting data, reaching a conclusion and communicating these activities. Investigations can include practical and/or secondary-sourced data or information.
law	A statement describing invariable relationships between phenomena in specified conditions, frequently expressed mathematically.
model	A representation that describes, simplifies, clarifies or provides an explanation of the workings, structure or relationships within an object, system or idea.
molar mass	The mass of one mole of a substance. It may be represented as M, M(x) or MM.
plan	Decide on a course of action, and make arrangements relating to that course of action, in advance.
practical investigation	An investigation that involves systematic scientific inquiry by planning a course of action and using equipment to collect data and/or information. Practical investigations include a range of hands-on activities, and can include laboratory investigations and fieldwork.
primary sources/primary data	Information created by a person or persons directly involved in a study or observing an event.
qualitative	Relating to, measuring, or measured by the quality of something.
quantitative	Relating to, measuring, or measured by the quantity of something.
redox	A reaction in which one substance is reduced and another is oxidised or de-oxidised.
reliability	An extent to which repeated observations and/or measurements taken under identical circumstances will yield similar results.
secondary-sourced investigation	An investigation that involves systematic scientific inquiry by planning a course of action and sourcing data and/or information from other people, including written information, reports, graphs, tables, diagrams and images.
technology	All types of human-made systems, tools, machines and processes that can help solve human problems or satisfy needs or wants, including computational and communication devices.
theory	A set of concepts, claims and/or laws that can be used to explain and predict a wide range of related observed phenomena. Theories are typically founded on clearly identified assumptions, are testable, produce reproducible results and have explanatory power.
validity	An extent to which tests measure what was intended or to which data, inferences and actions produced from tests and other processes are accurate.
variable	In an investigation, a factor that can be changed, kept the same or measured – eg time, distance, light, temperature.
vector	A quantity which possesses both magnitude and direction. Two such quantities acting on a point may be represented by the two sides of a parallelogram, so that their resultant is represented in magnitude and direction by the diagonal of the parallelogram.