Recently, more and more attention has been paid to emotions in the domain of Human-Computer Interaction. When evaluating a product, one can no longer ignore the emotions a product induces. This paper examines the value of a new instrument to measure emotions: the FaceReader. We will assess the extent to which the FaceReader is useful when conducting usability evaluations. To do this, we will compare the data gained from the FaceReader with two other sources: user questionnaires and researcher’s loggings. Preliminary analysis shows that the FaceReader is an effective tool to measure instant emotions and fun of use. However, a combination of the FaceReader with another observation method (e.g. researcher’s loggings) is necessary. As regards the user questionnaire, our results indicate that it is rather a reflection of the content of the application or the outcome of a task, than a correct selfreflection of how the user felt when accomplishing the task. Author Keywords Emotions, usab...