In reply to verif_learner:
This is a very broad (every design is different) and deep (who verifies the code that verifies the scoreboard). At a minimum, you should be able to check the connections, have your monitor send random data and make sure your scoreboard is receiving all the transactions it needs to perform its checks. In some cases, you can use your predictors to generate both actual and expected data. Then randomly disturb the actual data to make sure the scoreboard catches the error.