This special issue of the journal Memory celebrates thirty years of research into the levels of processing (LoP) framework. Evaluations are provided by leading researchers, including the original proposers, Craik and Lockhart. In addition new findings are reported and extensions of, as well as alternatives to, LoP are described. Overall the collected papers show that much remains to recommend the processing approach to memory, and fruitful theorizing with empirical consequences are readily derivable from the LoP framework.