observable

noticeable (more common in everyday speech) | visible (usually refers specifically to being seen) | detectable (often suggests finding something with effort or instruments)

unobservable (cannot be seen or noticed) | invisible (cannot be seen) | imperceptible (too slight to be noticed)

observable change |observable difference |observable effect |observable sign |observable trend |observable pattern |observable behavior |observable improvement |clearly observable |directly observable

perception |description

measurable (emphasizes numerical or practical measurement) | detectable (emphasizes that something can be found or identified) | empirical (relates to evidence from observation or experiment)

theoretical (exists as an idea or model rather than direct evidence) | unmeasurable (cannot be measured) | unobservable (cannot be directly observed or detected)

observable data |observable evidence |observable phenomenon |observable variable |observable outcome |observable symptoms |observable characteristics |observable facts |empirically observable |not directly observable

science |research |measurement

variable (a broader term for a measurable factor that can change) | measurement (emphasizes the recorded value rather than the property itself) | indicator (something used as evidence of another condition)

unobservable (something that cannot be directly observed or measured) | latent variable (a hidden factor inferred from observables)

a physical observable |quantum observable |market observables |key observables |measured observables |clinical observables |direct observables |observable of interest |set of observables |statistical observables

science |mathematics |computing |measurement