Description: This poster presents research conducted on students at Ramkhamhaeng University (RU). Abstract: Previous studies have found that perceived source accessibility strongly correlates with the frequency of use of information sources and has influenced use of information channels, rather than expected quality or amount of information. Regional students succeed in their studies when they can easily access information through convenient sources. Therefore, the researcher will investigate factors affecting regional students' selection of information sources to meet their information needs, as well as investigate these regional students' satisfaction with Ramkhamhaeng University (RU) Regional Library Services and the perceived quality of information retrieved from other information sources. The researcher applies the 'Principle of Least Effort' for this study. This principle governs and predicts the choices of these regional students' perceived source accessibility, wehreas 'Simon's Satisficing Theory' explains the selection and use of the information retrieved without considering whether the information is optimal.