An experimental replication of a previous study in which the researcher intentionally changes one or more features of a prior experiment.

An experimental replication of a previous study in which the researcher exactly duplicates a previous study using the same subjects as the original study.

An experimental replication of a previous study in which the researcher exactly duplicates a previous study but uses different subjects from the original study.

The extent to which the results of a study can be generalized to other settings, behaviors, or subjects.

A researcher exactly duplicates the procedures from a previous study, using the same or different subjects with the same demographics.

PTB founder Dana Meller helps connect each of the validities to the validity of this explanation.

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.

Refers to when initial response rates in baseline are weaker due to a subject needing to get warmed up.

Refers to an improvement in responding from the opportunity to practice a behavior, specifically during prolonged baseline measurement periods.

Refers to the changes in a subject over the course of the study that result from natural growth and development.

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…

Result can elicit a reflexive behavior.

Reinforcement that is accessed without meeting the response requirements of the contingency.

Refers to the changes in operant responding due to the repeated presentation of a particular antecedent stimulus.

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.

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.