There are many techniques to study materials. In this chapter the focus of experimental techniques to verify crack sealing (recovery against environmental actions) or crack healing (recovery against mechanical actions) has been limited to techniques that have been used and reported in self-sealing and self-healing research. To get a look and feel of the topic the chapter starts with a section on techniques which can be used to examine crack healing such as microscopy, X-ray diffraction and Raman spectroscopy. Next, the attention shifts from observing that something has been repaired to how well the repair has been. Following the definitions set out in chapter one, a differentiatiion has been made between techniques to verify recovery against environmental or mechanical actions. For recovery against environmental actions it turns out that permeability tests are often applied, while for recovery against mechanical actions the regain in strength by mechanical testing is the preferred choice.