No prior research has been identified that investigates the causal factors for workplace exploratory search task performance. The impact of user, task, and environmental factors on user satisfaction and task performance was investigated through a mixed methods study with 26 experienced information professionals using enterprise search in an oil and gas enterprise. Some participants found 75% of high‐value items, others found none, with an average of 27%. No association was found between self‐reported search expertise and task performance, with a tendency for many participants to overestimate their search expertise. Successful searchers may have more accurate mental models of both search systems and the information space. Organizations may not have effective exploratory search task performance feedback loops, a lack of learning. This may be caused by management bias towards technology, not capability, a lack of systems thinking. Furthermore, organizations may not “know” they “don't know” their true level of search expertise, a lack of knowing. A metamodel is presented identifying the causal factors for workplace exploratory search task performance. Semistructured qualitative interviews with search staff from the defense, pharmaceutical, and aerospace sectors indicates the potential transferability of the finding that organizations may not know their search expertise levels.