Understanding whether a conclusion in a paper you read or an experiment you run is a valid one is, well, let’s just say pretty important, and more than a little confusing. In this episode, we talk through the Big Four Validities (™):  Internal, External, Statistical Conclusion, and Construct Validity.  It may sound similar, but we promise this is more fun than your last research methods lecture! 

In this episode we mention: 

Shadish WR, Cook TD, & Campbell DT (2002). Experimental and quasi-experimental designs for generalized causal inference. Boston, MA: Houghton-Mifflin

Email us letters about developmental science at [email protected]. More episodes and podcast information at WithinandBetweenPod.com. Our theme music was composed by Jason Flowers. Our logo was created by Nathan Archer. This episode was recorded January, 4, 2026.