How can you check that use case dialogues are correct?
Once you have written some essential use cases, you need to verify that they make sense, that they describe all the communication that is needed for an actor user and the system to carry out the use case, and that they don't include any unnecessary implementation details. You don't just write use cases for the fun of it: the point of the use case model is to direct the development effort, so inconsistencies or errors in use cases can cause problems if they are not caught later on. It's important different team members have the same understanding of use case dialogs, or inconsistencies and errors are more likely to be introduced.
Therefore: Act each use case before an audience of the development team.
In a use case roleplay, one person takes the role of the user, and another person takes the role of the system. They then proceed to act out the interaction, using the use case body as a script. Other people critically observe the role play. Although use cases should not be very long, use case roleplay is quite useful for checking the use case.
There are several things to watch for in use case role play. One is continuity, to make sure that both user and system understand when they have something to do, and to make sure they understand what needs to be done. Confused pauses can indicate misunderstanding, which can often highlight unresolved issues in describing the use case. Another thing to watch for is assumed information. Sometimes the user or the system will mention information they are relying on, yet have would not actually know. It is important to check these details, because they can again show that the use case has not yet been fully described.