Final answer:
The revised semantic network theory by Collins and Loftus received criticism regarding inconsistencies in definition, difficulties in empirical measurement, and the personal variability of semantic networks. Loftus' research on memory's malleability further fueled debates over the theory's applications and generalizability.
Step-by-step explanation:
The revised semantic network theory developed by Collins and Loftus has faced criticism for different reasons. One criticism focuses on the vagueness and variability in defining and describing the theory, as well as challenges in empirically measuring and studying the related concepts. Another important criticism is based on how the theory integrates personal experiences into semantic networks, implying that everyone's network is unique and thus difficult to generalize. Cognitive psychologist Elizabeth Loftus, known for her research into false memories, supports the idea that memory is not static and can be manipulated post-event, which continues to be a point of debate. The notion of spreading activation, where activating one part of the semantic network can trigger the activation of related concepts, underpins the theory but does not account for the directions and extent of the activation, which is often variable and less predictable than the theory suggests.