 Falsificationism  is a well-known view in the philosophy of science. The core idea is that for a hypothesis to be scientific, rather than pseudo-scientific or metaphysical, it must be falsifiable in the following sense: “statements …, in order to be ranked as scientific, must be capable of conflicting with possible, or conceivable observations”. (Popper 1962, 39). The main difference with our development is the philosophical objective: the goal of learning theory is not to demarcate scientific hypotheses from pseudo-scientific theories, but to characterize the standards of empirical success we can expect from inquiry for a given set of hypotheses. A hypothesis that is refutable according to the definition above allows inquiry to provide a  negative test: when the hypothesis is incorrect, inquiry will eventually indicate its incorrectness with certainty (given background knowledge). The specific definition of “falsifiability” in the Popper quote above is not equivalent to refutability in the learning-theoretic sense [Schulte and Juhl 1996]. For example, the hypothesis \(H =\) “the first raven is black and some other raven is non-black” conflicts with the possible observation that the first raven is white. However, if in fact all observed ravens are black, then \(H\) is incorrect but not falsified by any finite number of observations, hence not refutable according to the learning-theoretic definition. For further discussion of the relationship between Popperian falsification and learning theory see [Genin 2018].