Reading focus
Syllabus: How Do We Learn What Predicts What?
Compare control histories, responding at test, and the authors’ explanations for the missing blocking effects. Keep procedural failures and evidence about a model’s boundaries distinct.
Why you’re reading it. Evaluate the empirical reach of the effect used to motivate the model. The optional commentary and reply offer a focused dispute about whether the failures could have been predicted.
A question to consider. Choose one reported procedural feature that could affect blocking. What result in a new comparison would support it as a boundary condition rather than a convenient explanation after the fact?
Why this reading
An effect’s importance to a theory does not establish how reliably a particular procedure produces it. These experiments make the conditions for observing blocking an empirical question and invite scrutiny of what a null result can tell us.
Before you read
In blocking, prior training with A can reduce responding to X after reinforced AX training, relative to a comparison condition. A floor effect occurs when responding is too low to reveal the contrast. Statistical power depends on assumptions about effect size; a nonsignificant result is not automatically evidence of equivalence.
Read for
- Compare the experimental and control histories rather than treating low responding to X alone as evidence of blocking.
- Track the changes across rodent procedures and laboratories, and separate experiments with informative test responding from those limited by a floor effect.
- Distinguish the reported results from proposed explanations involving procedural conditions, generalization, and publication bias.
Consider afterwards
- A blocking comparison produces equally low responding in both groups. What additional observation would help distinguish an absent blocking effect from an uninformative test?
Editorial context
The authors do not claim that blocking never occurs. Soto’s commentary argues that stimulus representation and other conditions make many failures predictable; the authors’ reply disputes the adequacy and advance specificity of that explanation. The disagreement concerns boundary conditions and explanatory constraints, not a simple choice between trusting all positive or all null results.