'Information commitments' include both a set of evaluative standards that Web users utilize to assess the accuracy and usefulness of information in Web-based learning environments (implicit component), and the information searching strategies that Web users use on the Internet (explicit component). An 'Information Commitment Survey' (ICS), consisting of aforementioned components, was developed. The participants of this study were 610 university students, coming from four universities in Taiwan, and their information commitments were surveyed. Through a series of structural equation modelling (SEM) analyses with Linear Structure RELationships (LISREL), this study confirmed the reliability and validity of ICS. More importantly, the causal relationships between the two components of ICS were also examined. The findings showed that learners' evaluative standards on Web materials (implicit component) had significant effects on their information searching strategies in Web-based learning environments (explicit component). For example, learners who utilized an advanced evaluative standard, such as using multiple sources to judge the accuracy of Web materials, were significantly more oriented toward using a sophisticated information searching strategy, such as carefully exploring and elaborating information in Web-based learning environments. In other words, learners' evaluative standards for Web materials should be viewed as important predictors for their searching strategies in Web-based learning environments.