Trustworthiness is one of the main issues upon which the decision whether to adopt an Open-Source Software (OSS) product is based. The work described here is part of an activity that has the goals of 1) defining an adequate notion of trustworthiness of software products and artifacts and 2) identifying a number of factors that influence it. Specifically, this paper reports about the identification of the \u201cdimensions\u201d of trustworthiness, i.e., of the high-level qualities that software products and artefacts have to posses in order to be considered trustworthy. These dimensions are described by means of a conceptual model of trustworthiness, which comprises the representation of the factors that affect the user\u2019s perception of ...