Metacognition is one of the promising contemporary research fields in psychology and education. The concept has been introduced to describe and explain how people gain control over their learning and thinking, particularly in the case of cognitive failures and difficulties they meet when dealing with information processing and problem solving (Efklides & Sideridis, 2009; Flavell, 1976). However, although every one agrees that there has to be something as "metacognition" (like the lognes monster?), no one agrees as to what exactly metacognition is about. In addition researchers currently use different concepts for overlapping phenomena (Desoete, 2007; 2008; Desoete & Roeyers, 2006; Desoete & Veenman, 2006). Is self-regulation the same as metacognitive skills? How does calibration fit in? (Contains 1 table.)