fundamental classifications of knowledge may be measurable as factors of production and can reveal evidence of specialization between adjacent stages of production even in the presence of shared substantive knowledge. the present study aims to distinguish between, and empirically measure, relative reliance on fundamental classifications knowledge at the individual level. in this study, investment managers were asked in an online survey to weigh their relative reliance on tacit, codified, and encapsulated knowledge in executing different investment strategies for diverse client groups. measures of relative reliance on each fundamental classification of knowledge were derived from weights assigned by each survey respondent in a series of six questions. survey respondents provided reliable measures of their relative reliance on tacit, codified, and encapsulated knowledge. reliance on these fundamental classifications of knowledge is shown to differ between investment managers, depending on the investment strategies being employed and client groups served. these differences were exhibited notwithstanding all the respondents sharing common substantive knowledge. measures of relative reliance on three classifications of knowledge were based on self-reported ratings rather than on objectively observed phenomena, making them subject to measurement error. therefore, researchers are encouraged to observe relative reliance on tacit, codified and encapsulated knowledge in future studies. the divergences in relative reliance on the fundamentally different knowledge-based factors of production were found in the presence of jointly-held substantive knowledge, suggesting that fundamental classifications of knowledge are measurable and can provide evidence of specialization.