By Matt Harrington, BCBA · Behaviorist Book Club · Research-backed answers for behavior analysts
Bob Bailey is a biologist and animal trainer who directed the US Navy Marine Mammal Program and collaborated with Keller and Marian Breland at Animal Behavior Enterprises. His relevance to BCBAs lies in his lifelong application of operant conditioning principles to real-world training problems, his insistence on data-driven practice, and his development of tools like the Keep Going Signal. Bailey's work demonstrates that the behavioral principles underlying applied behavior analysis are universal across species and contexts, strengthening the scientific foundation that BCBAs rely on in clinical practice.
The US Navy Marine Mammal Program trained dolphins and sea lions for military applications including mine detection, equipment recovery, and diver protection. The program's demands for reliable, precise behavioral performance under variable environmental conditions drove the development of systematic training protocols, detailed data collection methods, and a highly technical understanding of reinforcement timing and stimulus control. These contributions entered the broader behavior analysis knowledge base through Bailey's workshops and publications, influencing how practitioners think about training precision and the conditions required for behavioral reliability.
The Keep Going Signal is a conditioned reinforcer delivered during a behavioral chain to signal that the learner is on track and that completing the chain will produce the terminal reinforcer. Unlike a bridging stimulus that marks the end of a behavior, the KGS is delivered mid-behavior to maintain responding and improve fluency. In ABA practice, the KGS is used to support complex skill chains, increase behavioral persistence, and reduce the frequency of prompts needed during chain completion. A clicker or brief verbal marker delivered at specific points within a chain functions as a KGS when properly conditioned.
Keller and Marian Breland documented instinctive drift — the tendency for trained animals to revert to species-typical behaviors that compete with the reinforced operant — in their landmark 1961 paper. This finding demonstrated that operant conditioning does not occur in a biological vacuum: evolutionary predispositions constrain what can be trained and how reliably it can be maintained. For behavior analysts, instinctive drift is a reminder that biological variables interact with operant history and that some behaviors are more difficult to establish or maintain in certain organisms due to evolutionary heritage. This concept informs discussions of response effort and behavioral persistence in human learners.
Bailey's insistence on recording every training trial and reviewing acquisition data daily translates to clinical supervision through the expectation that BCBAs maintain robust data systems and review them at a frequency that allows early detection of problems. Supervisors should examine session data before each supervision meeting, identify trends in acquisition curves, and make evidence-based programming decisions rather than relying on supervisee impressions. Treatment integrity data — measuring whether procedures are being implemented as written — is also a direct application of Bailey's precision standards and is required under the BACB Ethics Code.
Bailey's scientific mindset means treating every training protocol as a hypothesis: if this procedure is correct, the data should show a specific pattern, and if it does not, the procedure needs revision. In daily BCBA practice, this means formulating clear, testable predictions about treatment outcomes, collecting data systematically, reviewing it at regular intervals, and being willing to modify programs based on what the data show rather than what seemed clinically intuitive. It also means maintaining skepticism toward procedures that lack empirical support and seeking out research when encountering novel clinical challenges.
Bailey's position is that when behavior fails to develop or maintain as expected, the trainer's job is to identify what in the environment, the procedure, or the reinforcement contingency was insufficient — not to attribute the failure to the learner's capacity. In animal training, the animal cannot be blamed for failing to learn; only the training procedure can be examined. Applied to clinical ABA, this principle directs BCBAs to interrogate their programs before concluding that a learner is not capable of progress. It is an anti-deficit stance rooted in functional analysis thinking and is consistent with the ABA field's commitment to environment-focused explanations of behavior.
Bailey has consistently argued that behavior analysis benefits from dialogue with ethology, comparative psychology, evolutionary biology, and other disciplines that study behavior from different angles. Cross-disciplinary collaboration in clinical ABA means consulting with speech-language pathologists, occupational therapists, neurologists, and educators when their domain knowledge is relevant to a client's needs. It also means being intellectually curious about findings from adjacent fields that may inform behavioral assessment or programming. The BACB Ethics Code supports this through Code 2.01, which requires that assessments draw on information from multiple sources and professionals.
Reinforcement timing is central to Bailey's approach. He has repeatedly emphasized that the difference between a reinforcer delivered within a fraction of a second of the target response and one delivered even one or two seconds later can mean the difference between reinforcing the correct behavior and reinforcing an adjacent, incorrect behavior. This precision requirement applies directly to clinical ABA: the timing of consequence delivery by RBTs and BCaBAs affects what is actually being reinforced in each trial. Treatment integrity assessments should include measurement of reinforcement timing as a discrete procedural variable, not just topographic fidelity to the written protocol.
Interview formats capture the heuristics, decision rules, and reasoning processes of expert practitioners in a less filtered way than formal publications allow. Published research presents conclusions and methods; interviews reveal how an expert thinks — how they weigh competing considerations, what they have learned through failure, and what principles guide their practice across contexts. For BCBAs, engaging with Bailey's interview provides access to the kind of expert clinical reasoning that is difficult to acquire from textbooks alone. It models how a deeply experienced practitioner integrates scientific principles with practical problem-solving in real training environments.
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All behavior-analytic intervention is individualized. The information on this page is for educational purposes and does not constitute clinical advice. Treatment decisions should be informed by the best available published research, individualized assessment, and obtained with the informed consent of the client or their legal guardian. Behavior analysts are responsible for practicing within the boundaries of their competence and adhering to the BACB Ethics Code for Behavior Analysts.