Maturation Refers to the changes in a subject over the course of the study that result from natural growth and development. 5th Edition Task ListD-2 Distinguish between internal and external validity. 6th Edition TCOD.3 Identify threats to internal validity (e.g., history, maturation). Related Content Warm-up effects Refers to when initial response rates in baseline are weaker due to a subject needing to get warmed up.Subject confounds Any uncontrolled participant-related variables that may interfere with the outcomes of an intervention and therefore the internal validity of an experiment.Setting confounds Any uncontrolled variables in the treatment setting that could impact the outcomes and/or the effectiveness of an intervention and therefore the internal validity of the experiment.Reactivity Refers to the changes in an individual’s behavior due to the presence of an observer.Practice effects Refers to an improvement in responding from the opportunity to practice a behavior, specifically during prolonged baseline measurement periods.Measurement confounds Uncontrolled variables related to the environment, the measurement tools, or a data collector’s behavior that may interfere with the measurement of behavior and therefore impact the outcomes and/or the effectiveness…Independent variable (IV) confounds Uncontrolled environmental variables that may interfere with the outcomes and/or the effectiveness of an intervention and therefore the internal validity of the experiment.Extraneous variables Any aspect of the environment that must be held constant to prevent unplanned environmental variations during experimentation, usually something the experimenter is aware of and for which they do their…Confounding variables Result can elicit a reflexive behavior.Bootleg reinforcement Reinforcement that is accessed without meeting the response requirements of the contingency.Attrition A reduction in the number of study participants, which can impact the validity and reliability of the findings and compromise the integrity of the data.Adaptation Refers to the changes in operant responding due to the repeated presentation of a particular antecedent stimulus.Systematic replication An experimental replication of a previous study in which the researcher intentionally changes one or more features of a prior experiment.Internal validity The extent to which an experiment strongly shows that changes in the dependent variable are a direct result of the independent variable and not the result of some other uncontrolled…Intrasubject direct replication An experimental replication of a previous study in which the researcher exactly duplicates a previous study using the same subjects as the original study.Intersubject direct replication An experimental replication of a previous study in which the researcher exactly duplicates a previous study but uses different subjects from the original study.External validity The extent to which the results of a study can be generalized to other settings, behaviors, or subjects.Dana Do's: All the Validities in ABA, Explained PTB founder Dana Meller helps connect each of the validities to the validity of this explanation.Dana Do's: How to Decipher the Many Forms of Validity It's particularly meaningful to be able to tell validity, social validity, internal and external validity apart. PTB co-founder Dana Meller has some tips to do just that.Let's Break Down a BCBA® Mock Exam Question: Identifying Measurement Confounds in Experimental Design PTB co-founder Dana Meller breaks down a BCBA® mock exam question that explores the difference between measurement confounds and subject confounds, how they relate to threats to internal validity in ABA research. Refer to BCBA® Task List (5th ed.) Section D-2: Distinguish between internal and external validity.Experimental Validity: The Relationship between Behavior Change & Independent Variables PTB co-founder explains the different types of validity in ABA. Refer to BCBA® Task List (5th ed.) Section D-2: Distinguish between internal and external validity.