Study Design. Pilot study. Objective. To examine whether surgical outcomes can be assessed objectively by advanced tracking technology, based on Global Posi-tioning Systems (GPS). Summary of Background Data. Outcome studies are the com-monest way to assess the results of surgical procedures. The suc-cess of these efforts is impeded by a number of factors, including the lack of valid outcome measures, diffi culty in assessing changes in patients' expectations (response shift) and confounding effects of secondary gains. Methods. The measurement of walking speed, distances, and num-ber of walking events per day, claudication index (maximal walking distance), characteristics during motorized trips, and the amount of time spent outdoors were monitored in 2 patients undergoing spine surgery for several weeks using advanced tracking technologies. Results. In 1 patient, all parameters increased progressively from the time of surgery to the end of the recording period. These fi ndings were consistent with her recovery from surgery. In a second patient, tracking showed the patient's diffi culty in mobilizing, leading to the diagnosis of another orthopedic problem, and to total hip replacement surgery. Conclusion. The technology presented in this pilot appears to be useful in understanding a patient's level and breathe of activity. These data will assist in better understanding the limitations imposed by specifi c musculoskeletal pathology and in monitoring perioperative function and complications and their related causes. Spatial data may indirectly refl ect a patient's social and mental conditions. This interdisciplinary pilot may lead to the development of valid outcome measures for a range of medical conditions. Studies comparing ques-tionnaires to this new outcome measure may shed light on issues like response shifts and secondary gain. Norms and clusters of spatial behaviors in different pathologies may enable better patient selection for medical, mental, and surgical interventions. T he outcome of surgery can be assessed in various ways. Data can be obtained from various persons—the patient, the treating physician, or an independent ob-server 1 and using various methods (questionnaires, observa-tions, measures of physical performance, radiographs). The quality of data obtained by these methods varies. Ideally, an outcome tool should be valid, simple, quick, reliable, reproducible, and sensitive to change. 2 One of the most popular ways of measuring outcomes is through the use of self administered questionnaires. They include the following 3 major types: general health, 3 disease specifi c, 4 and patient satisfaction. Many of the commonly used outcome question-naires in orthopedic surgery (for example, that of Harris) 5 have never been validated. Moreover, although they may be reliable, patients' self assessments do not necessarily refl ect their actual condition. For example, in 1 study, patients with intermittent claudication due to lumbar spinal canal stenosis were asked to assess their walking distances. Although self-reports yielded a wide range of walking abilities, most pa-tients were able to walk the same distance of about 200 m. This raises questions about the validity of patient self-report questionnaires in this area. 6 A response shift is a psychological change in one's perception of the quality of life following a change in health status. The idea goes back to the days of Plato. 7 This phenomenon initially was recognized in patients with terminal diseases who, despite a worsening of the physical condition, did not necessarily report deterioration in quality of life—a positive response shift. 8 Response shift was recently studied in total knee arthroplasty—a negative response shift, 9,10 and the basis for its study in spine surgery has been described, 11 with a review of current data in orthopedic and spine surgery published recently. 12 This psychological process, resulting in a change in the expectations of people when com-pares between the pre-and the postoperative period, leads to

A growing body of research is focusing on tourism in urban destinations. However, there has been no research examining the impact of hotel location on subsequent tourist behaviour. This article fills this gap both theoretically and empirically, through an analysis of the time-space activity of tourists staying at four hotels in different areas of Hong Kong. The movements of 557 tourists' day-trips were tracked using GPS loggers. The study concluded that hotel location has a profound impact on tourist movements, with a large share of the total tourist time budget spent in the immediate vicinity of the hotel. Further, the study illustrated the impact of geomorphic barriers on tourist movements. The findings have important implications at both a destination and enterprise level.