The Mathieson and Wall model outlines a 5-stage process for tourist decision making: 1) problem recognition, where a need for travel is identified; 2) information search, where sources are consulted to learn about options; 3) evaluation of alternatives, where a destination is selected; 4) purchase/booking arrangements, where travel is planned; and 5) post-purchase experience, where satisfaction is evaluated. This linear model examines how internal and external factors influence each stage of a tourist's purchase process.