Social Tagging as a decentralized collaborative and collective approach to describe, structure, and share digital objects with user created keywords has become increasingly popular since 2004. Once evolved from a social bookmarking application service, meanwhile it is used for several private and corporate purposes. It is also applicable for e-HRM tasks, e.g. augmenting employees' profiles and
... [Show full abstract] competency models with tags. In this paper we pursue to detect its applicability to support competency acquisition. In detail we firstly answer the question, which characteristics social tagging systems offer to gather competency related information in order to describe competency profiles. To answer this question we present a conceptual framework that focuses on social tagging systems from an external and internal view. Secondly, we analyze if social tagging systems are able to ensure the provisioning of reliable and valid competency related information from the classical testing theories point of view. It has been detected, that both the ambiguity of language and the absence of rules aggravate the estimation of reliability and validity. Nevertheless, other strengths social tagging systems offer have been found. They equalize the lack of information quality and make social tagging systems valuable for competency acquisition.