To quantify means to measure or express something in terms of quantity or numerical value. In psychology, quantifying refers to assigning numerical values to psychological phenomena for the purpose of measurement and analysis.
Related terms
Measurement: The process of assigning numbers or values to variables in order to obtain quantitative data.
Psychometrics: The field of study that focuses on the measurement of psychological traits, abilities, and processes.
Operationalization: The process of defining and measuring a construct (e.g., intelligence or happiness) by specifying the operations or procedures used to observe and measure it.