  This is a detailed analysis and comparison of the ACT-R and Soar cognitive
architectures, including their overall structure, their representations of
agent data and metadata, and their associated processing. It focuses on working
memory, procedural memory, and long-term declarative memory. I emphasize the
commonalities, which are many, but also highlight the differences. I identify
the processes and distinct classes of information used by these architectures,
including agent data, metadata, and meta-process data, and explore the roles
that metadata play in decision making, memory retrievals, and learning.
