Dhamma Vicaya (dah-mah vih-chah-yah) is the second of the Seven Awakening Factors, and I prefer to interpret the Pali to mean Investigation of Mental Phenomena.  It functions closely with the Mindfulness and Energy Awakening Factors.  During the training meditation, I suggest that intentionally aiming attention to evident sensations at the beginning of the in-breath and sustaining attention for the duration of the in-breath, then repeating this for the out-breath begins the process of maturing attention towards dhamma vicaya.  Once attention to the breathing cycle becomes more routine, it is suggested that one “look closer” at an aspect of breath sensation that was more evident to increase the power of insight.  It is also emphasized that dhamma vicaya isn’t really about the breath sensations specifically, but rather noticing with clarity and detachment how the mind creates a meaningful self in relationship to the sensations.