Deduction and induction – a deduction is a conclusive inference while an induction is a conclusion from one or more pieces of evidence.
Operational definition and dictionary definition – an operational definition is a definition based on measurement criteria that have empirical reference while a dictionary definition is based on synonyms.
Concept and variable – a concept is a generally accepted collection of meanings or characteristics associated with certain events while a variable is value or set of values related to a property being studied.
Hypothesis and proposition – A hypothesis is a is a declarative statement that states a belief while a proposition is a statement about concepts that may be regarded as true or false.
Theory and model – a theory is a set of systematically inter-related concepts, definitions and propositions that are advanced to explain and predict phenomena while a model is a representation of a system that is constructed to study some aspect of the system.
Scientific method and scientific attitude – The scientific method deals with rationalism and empiricism: formal structured proofs and observable, concrete data; the scientific attitude deals with curiosity