The
levels-of-processing effect, identified by
Fergus I. M. Craik and Robert S. Lockhart in 1972, describes
memory recall of
stimuli as a function of the depth of mental processing. Deeper levels of analysis produce more elaborate, longer lasting, and stronger memory traces than shallow levels of analysis. Depth of processing falls on a shallow to deep continuum. Shallow processing (e.g., processing based on
phonemic and
orthographic components) leads to a fragile memory trace that is susceptible to rapid decay. Conversely, deep processing (e.g.,
semantic processing) results in a more durable memory trace.