Environment An elaborate and always changing universe of stimulus conditions and events that are internal and external to an individual. B-2 Define and provide examples of stimulus and stimulus class. Related Content Dana Do's: What's the Difference Between Formal and Feature Stimulus Class? The difference between formal and feature stimulus class is something that has caused many students a great deal of confusion. That is because they seem the same, unless you look closely and realize they are not. PTB co-founder Dana Meller explains. Refer to 5th Edition Task List Section B-2: Define and provide examples of stimulus and stimulus class.Breaking Down the Intricate Connection Between Environment & Behavior PTB co-founder Dana Meller discusses the term environment in connection with a term defined as a physical event that influences how individuals interact with the world around them Refer to BCBA® Task List (5th ed.) Section B-2: Define and provide examples of stimulus and stimulus class.Formal stimulus class A group of stimuli that share physical/topographical features.Temporal stimulus class A group of stimuli that share common timing in relation to the behavior they precede or follow.Arbitrary stimulus class A group of stimuli that do not share any common topographies but evoke the same response. Feature stimulus class A group of stimuli that share an infinite number of possible relations and evoke the same response.Stimulus External or internal environmental event(s) that affect an individual’s behavior.Stimulus class A group of stimuli that share a common function, topography, or temporal relation and have a common effect on a response class (behavior). Hint: Think of the stimulus class as … Environment Read MoreTest your ABA Terminology ➠ Identify the Stimulus Class Test your knowledge of concepts and principles as PTB co-founder Dana Meller reviews a question about identifying a specific type of stimulus class, and the features associated with the three main stimulus class variations. Refer to BCBA® Task List (5th ed.) Section B-2: Define and provide examples of stimulus and stimulus class.