Consider an HCI consultant with extensive experience in evaluating web sites and graphical user interfaces (GUI). She has just received an evaluation contract for a new accounting product made by Company A due to her prior experience with e-commerce site evaluation. The work involves assessing the training requirements and the usability of the system. During the initial configuration of her usability laboratory she becomes aware that that software she is to evaluate contains a GUI already patented by a rival Company B, which she evaluated several weeks before. Under her contractual arrangements she is not allowed to discuss the evaluation of a product with anyone outside the contract. She therefore has an obligation to Company B not to provide information regarding their product to anyone else without their permission. She has a similar obligation to Company A. Can she continue with the evaluation? If she cannot continue with the evaluation how does she inform Company A of the patent violation? Does she have an obligation to let company B know Company A has copied their GUI? We ask the students to analyse the above case study using either two or four classical ethical theories. So, it is always from the four classical ethical theories such as utilitarianism, deontology, virtue and contract.