  Task-oriented dialogue systems (TODS) have become crucial for users to
interact with machines and computers using natural language. One of its key
components is the dialogue manager, which guides the conversation towards a
good goal for the user by providing the best possible response. Previous works
have proposed rule-based systems (RBS), reinforcement learning (RL), and
supervised learning (SL) as solutions for the correct dialogue management; in
other words, select the best response given input by the user. However, this
work argues that the leading cause of DMs not achieving maximum performance
resides in the quality of the datasets rather than the models employed thus
far; this means that dataset errors, like mislabeling, originate a large
percentage of failures in dialogue management. We studied the main errors in
the most widely used datasets, Multiwoz 2.1 and SGD, to demonstrate this
hypothesis. To do this, we have designed a synthetic dialogue generator to
fully control the amount and type of errors introduced in the dataset. Using
this generator, we demonstrated that errors in the datasets contribute
proportionally to the performance of the models
