I thought I understood the distinction but it is not quite what I thought it was.
THIS is the distinction:
* EDIT TO ADD: I think the concepts are very clear in this infographic but if people are having trouble with the words, hope this helps:
Respondent Conditioning = Classical Conditioning
"Response" = Behavior (includes emotional behaviors!)
"Reinforcing Stimulus" = reward = reinforcer = reinforcing consequence
The Operant-Respondent Distinction: How Do We Know?
by Dr. Eduardo J Fernandez
A common dilemma many animal trainers and other practitioners face is, “how do we know the difference between operant and respondent behavior?” In other words, how do we know if some learned behavior was produced through respondent (classical or Pavlovian) or operant conditioning?
To start, we can think of respondent conditioning as the occurrence of a conditioned response (CR) to a conditioned stimulus (CS) because of the pairing of that CS with an unconditioned stimulus (US) (Domjan, 2014). We can identify operant conditioning as an increase or decrease in some response as a function of the consequences that have followed that response (Pierce & Cheney, 2013). Historically, one of those distinctions involved involuntary vs voluntary behavior. That is, respondent conditioning involves involuntary responses, while operant conditioning involves voluntary behavior. Unfortunately, it is not that simple: We can operantly condition largely reflexive behavior, such as the heart rates of curare-immobilized rats (Miller & DiCara, 1967). Likewise, we can respondently condition voluntary behavior, such as the key pecking behavior of pigeons (Brown & Jenkins, 1968). In fact, respondent conditioning has even been used to train penguins to interact with enrichment devices (Fernandez, Kinley, & Timberlake, 2019).
In addition, behaviorists have debated other distinctions and proposed alternative approaches to thinking about these differences. While a detailed discussion is beyond the point of this blog, I have included several references below that discuss the merits of distinguishing between or abandoning certain respondent/operant distinctions (Domjan, 2016; Pear & Eldridge, 1984; readers might also be interested in one of the earliest debates and resolutions proposed: Mowrer’s  two-factor theory of conditioned avoidance).
Fortunately, and for both scientific and practical purposes, there is a simple solution: Focus on the *procedural* distinction. Respondent conditioning involves a stimulus-stimulus (s-s) pairing, whereas operant conditioning involves a response-stimulus (consequence; r-s) pairing.
This distinction is simple, exact, and tells us all we need to do to replicate any training practice. Are you counterconditioning some response? Counterconditioning is a respondent conditioning procedure, so focus on how you pair stimuli together. Are you shaping some response? Shaping is an operant conditioning procedure, so let us focus on how we deliver a stimulus (reward) for a response (in approximations!) And, when we wish to combine procedures, which is a commonly effective strategy, we can now accurately *describe* such combinations (i.e., desensitization plus reinforcement; see Tyner et al., 2016; also, Fernandez, 2020 for a discussion).
Science loves parsimony. Practitioners love practicality. The beauty of the s-s = respondent conditioning vs r-s = operant conditioning procedural distinction is that it is both parsimonious and practical. We could say it is pragmatically exact (PRAG-XACT!) It is a simple description that not only helps us do what we do, but also explains what we did so everyone can equally understand 😊
Brown, P. L., & Jenkins, H. M. (1968). Auto-shaping of the pigeon's key-peck. Journal of the Experimental Analysis of Behavior, 11(1), 1-8.
Domjan, M. P. (2014). The Principles of Learning and Behavior. Cengage Learning.
Domjan, M. (2016). Elicited versus emitted behavior: Time to abandon the distinction. Journal of the Experimental Analysis of Behavior, 105(2), 231-245.
Fernandez, E. J. (2020). Training petting zoo sheep to act like petting zoo sheep: An empirical evaluation of response-independent schedules and shaping with negative reinforcement. Animals, 10(7), 1122.
Fernandez, E. J., Kinley, R. C., & Timberlake, W. (2019). Training penguins to interact with enrichment devices for lasting effects. Zoo Biology, 38(6), 481-489.
Miller, N. E., & DiCara, L. (1967). Instrumental learning of heart rate changes in curarized rats: shaping, and specificity to discriminative stimulus. Journal of Comparative and Physiological Psychology, 63(1), 12-19.
Mowrer, O. (1947). On the dual natures of learning; A reinterpretation of conditioning and problem solving. Harvard Educational Reviews, 17, 102-148.
Pear, J. J., & Eldridge, G. D. (1984). The operant‐respondent distinction: Future directions. Journal of the Experimental Analysis of Behavior, 42(3), 453-467.
Pierce, W. D., & Cheney, C. D. (2013). Behavior Analysis and Learning. Psychology Press.
Tyner, S., Brewer, A., Helman, M., Leon, Y., Pritchard, J., & Schlund, M. (2016). Nice doggie! Contact desensitization plus reinforcement decreases dog phobias for children with autism. Behavior Analysis in Practice, 9(1), 54-57.