Abstract Proficiency scaling in the domain of intelligence analysis converges on an answer to the question of what counts as expertise in this domain. Proficiency scales in the domain are based on what are called essential competencies. There are many distinct analytical roles, entailing a specialization of expertise. This chapter discusses macrocognitive models of analyst reasoning and knowledge as a function of proficiency level, including recognition-primed decision making and intuition. This chapter also considers individual differences and conceptualize the different styles to be relatively stable and distinctive approaches to critical thinking. Proficiency scaling entails the issue of whether intelligence analysts are prone to cognitive biases. Analysts must cope with the problem of indeterminate causation, that is, the understanding of events for which there is no single cause, and causal forces include human agency and motivations. Directives in the intelligence community call for robust performance measures, but measuring analyst procedural skills is non-trivial. Finally, the implications for training are discussed.