Sensation: stimulation (any detectable input from the environment) of sense organs. Perception: the selection, organization, and interpretation of sensory input. Psychophysics: the study of how physical stimuli are translated into psychological experience. Threshold: a dividing point between energy levels that do and do not have a detectable effect. we all see the world subjectively, it is impossible for someone to see everything objectively. Each person perceives the world differently (based on experience, surroundings, people, etc. ) we all sense, but perceive things differently (perception is what we select, primarily based on our learning history) sensing is taking the energy from the world and experiencing it through our organs. we actually only pay attention to 10% of the things around us and ignoring 90% because it would be sensory overload if we were to pay attention to everything. Which 10% we pay attention to is individually unique based on experiences.