His work tends to focus on narrow areas of performance: chess, music, etc., where rote learning, memorization, drill, and repetition are the main keys, unlike 'messier' areas like research, engineering, teaching, and the like. But even within those narrow domains, his theory isn't sufficient to explain performance, individual differences, and expertise (http://www.sciencedirect.com/science/article/pii/S0160289613...). There are so many exceptions to the rule (like child prodigies http://www.sciencedirect.com/science/article/pii/S0160289613... ), so many domain differences (like he is acknowledging now in the target article). He ignores the last 30 years of research in cognitive psychology. For example, persistent misconceptions and bad habits that prevent us from learning and making significant progress in both conceptual and physical domains. His theory ignores genetic factors that influence performance and expertise (see http://www.sciencedirect.com/science/article/pii/S0160289613... or just watch a game of basketball), and ignores the role of IQ (http://www.sciencedirect.com/science/article/pii/S0160289613...). The data does not support Ericsson's theory, and his arguments have errors and contradictions (http://www.sciencedirect.com/science/article/pii/S0160289614...).