Building energy use is not only influenced by the building geometry, materials, external weather conditions, and HVAC systems but also by the occupant energy related behavior, such as operation of windows and shading devices. In addition, given the complex nature of occupant behavior, modeling occupancy is recognized as one of the major reasons for the potential discrepancy between simulated and actual building performance. In other words, use of reliable occupant behavior models is critical to achieve accurate building performance simulations. Accordingly, in recent years a large number of occupant behavior models have been developed. However, there are major uncertainties associated with the reliability of the occupancy related models as they have not been subjected to validation studies in different settings. To address this issue, the current work conduct an external evaluation of a widely used stochastic shading operation model. To this end, empirical occupant behavior data obtained from an office building in Hartberg, Austria is used to evaluate the model. Specifically, predictive performance of the shade operation model is evaluated by comparing the following predicted and observed parameters relevant to the operation of shading devices: i) Predicted action probabilities and the observed actions, ii) predicted and observed actions, and iii) predicted and observed shading states. According to the obtained results, the model underestimated the closing of interior shades, while it largely overestimated the deployment of exterior shades. More importantly, the results suggested that the model could not capture different seasonal patterns of occupants¿ operation of shades. With regard to the predicted shading states, two different approaches were adopted to test the model performance. However, it is concluded that, without including the model¿s feedback (for example via a building performance model) the predictive performance of the occupant behavior model cannot be properly captured.