According to an example aspect of the present invention, there is provided a system comprising a set of cans comprising at least two cans of which one can contains a specific scent, each can including a tab providing a dog a means to express choosing of the can, and transmitter for transmitting the information of whether the dog has expressed the can with the specific scent or a can with no said specific scent and an apparatus comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the apparatus at least to store the transferred information of multiple expressions, process the stored information in order to calculate at least how many of the multiple expression are correct, and display the results of the processed data.
