A head-to-head comparison is where two different approaches to meditation are compared. They are easier to conduct then sham meditation comparisons since elaborate deception strategies are not required, they have inherent authenticity and ethical problems are much less likely. Head-to-head trials are important and valuable because they allow comparison of different definitions, paradigms and approaches to meditation. They are especially useful given that there is no consensus even on what exactly meditation is. A disadvantage of such comparisons is that they may not necessarily allow for a clear distinction between meditation-specific and non-specific effects.