Scientific knowledge accrues via the falsification of theory-derived hypotheses.
Falsification is the process of proving a hypothesis wrong.
Falsifiability is the extent to which a hypothesis, or approach to research, can be falsified.
Falsifiability requires sufficient transparency (i.e., full disclosure, open materials, open data, and pre-registration)
Falsifiability is a non-optional essential aspect of the scientific approach (or else one is a historian rather than a scientist).
Falsification is achieved via meticulously executed series of direct replications.
Taxonomy of direct replications with respect to falsifiability (10 shades of falsifiability).
Replication is the activity of carrying out a direct replication.
Replicability is the extent to which a particular effect/hypothesis, or area of research, is replicable.
An effect is said to be replicable if an effect of similar magnitude can be consistently observed, under specified (boundary) conditions, across independent samples and researchers.
Scientific findings must be demonstrably replicable under conditions specified, but not necessarily replicable at will.1
1. For example, the bending of light 1919 solar eclipse findings, which eventually led to the falsification of Newton’s theory of gravitation in favor of Einstein’s General Theory of Relativity, is not replicable at will, but is (and continues to be) demonstrably replicable for solar eclipses satisfying conditions originally specified.