Metacognition
Metacognition is the knowledge (i.e. awareness) of one's cognitive processes and the efficient use of this self-awareness to self-regulate these cognitive processes (e.g. Brown, 1987; Niemi, 2002; Shimamura, 2000).

# Components
Metacognition is classified into three components:
- Metacognitive Knowledge (also called metacognitive awareness) refers to what individuals know about themselves and others as cognitive processors.
- Metacognitive regulation is the regulation of cognition and learning experiences through a set of activities that help people control their learning.
- Metacognitive experiences are those experiences that have something to do with the current, on-going cognitive endeavor.
Metacognition refers to a level of thinking that involves active control over the process of thinking that is used in learning situations.  Planning the way to approach a learning task, monitoring comprehension, and evaluating the progress towards the completion of a task: these are skills that are metacognitive in their nature. Similarly, maintaining motivation to see a task to completion is also a metacognitive skill.  The ability to become aware of distracting stimuli  both internal and external  and sustain effort over time also involves metacognitive or executive functions. The theory that metacognition has a critical role to play in successful learning means it is important that it be demonstrated by both students and teachers. Students who demonstrate a wide range of metacognitive skills perform better on exams and complete work more efficiently.  They are self-regulated learners who utilize the "right tool for the job" and modify learning strategies and skills based on their awareness of effectiveness.  Individuals with a high level of metacognitive knowledge and skill identify blocks to learning as early as possible and change "tools" or strategies to ensure goal attainment.  The metacognologist is aware of their own strengths and weaknesses, the nature of the task at hand, and available "tools" or skills.  A broader repertoire of "tools" also assists in goal attainment.  When "tools" are general, generic, and context independent, they are more likely to be useful in different types of learning situations.
Another distinction in metacognition is executive management and strategic knowledge. Executive management processes involve planning, monitoring, evaluating and revising one's own thinking processes and products. Strategic knowledge involves knowing what (factual or declarative knowledge), knowing when and why (conditional or contextual knowledge) and knowing how (procedural or methodological knowledge). Both executive management and strategic knowledge metacognition are needed to self-regulate one's own thinking and learning (Hartman, 2001).
Finally, there is a distinction between domain general and domain-specific metacognition. Domain general refers to metacognition which transcends particular subject or content areas, such as setting goals. Domain specific refers to metacognition which is applied in particular subject or content areas, such as editing an essay or verifying one's answer to a mathematics problem.

# Linkage to intelligence
Metacognition is often defined as thinking about thinking, and is used to help students learn. Much of the existing research on metacognition, at least in the domain of experimental psychology, has and cognition work (which are frequently incorrect). As another example, it refers to cognitive strategies students use to achieve a particular goal, such as asking oneself a question about a textbook passage.

# Relation to sapience
Metacognologists believe that the ability to consciously think about thinking is unique to sapient species and indeed is one of the definitions of sapience. There is evidence that monkeys and apes can make accurate judgments about the strengths of their memories of fact, while attempts to demonstrate metacognition in birds have been inconclusive.  However, a 2007 study has provided some evidence for metacognition in rats. 

# Definitions
Different fields define metacognition very differently. Metacognition variously refers to the study of memory-monitoring and self-regulation, meta-reasoning, consciousness/awareness and auto-consciousness/self-awareness. In practice these capacities are used to regulate one's own cognition, to maximize one's potential to think, learn and to the evaluation of proper ethical/moral rules.
In the domain of experimental psychology, an influential distinction in metacognition (proposed by T. O. Nelson & L. Narens) is between Monitoring--making judgments about the strength of one's memories--and Control--using those judgments to guide behavior (in particular, to guide study choices). Dunlosky, Serra, and Baker (2007) covered this distinction in a recent review of metamemory research that focused on how findings from this domain can be applied to other areas of applied research.
Metacognition is studied in the domain of artificial intelligence and modeling. Therefore it is the domain of interest of emergent systemics.

# Metacognitive strategies
The metacognitive-like processes are ubiquitous; especially, when it comes to the discussion of self-regulated learning. Being engaged in metacognition is a salient feature of good self-regulated learners. The activities of strategy selection and application include those concerned with an ongoing attempt to plan, check, monitor, select, revise, evaluate, etc. Metacognition is 'stable' in that learners' initial decisions derive from the pertinent fact about their cognition through years of learning experience. Simultaneously, it is also 'situated' in the sense that it depends on learners' familiarity with the task, motivation, emotion, and so forth. Individuals need to regulate their thoughts about the strategy they are using and adjust it based on the situation the strategy is applied to.
Recently, this notion has been applied to the study of second language learners in the field of  TESOL  and applied linguistics in general (e.g., Wenden, 1987; Zhang, 2001). This new development has been much related to Flavell (1979), where the notion of metacognition is elaborated within a tripartite theoretical framework. Learner metacognition is defined and investigated by examining their person knowledge, task knowledge and strategy knowledge. Wenden (1991) has proposed and used this framework and Zhang (2001) has adopted this approach and investigated second language learners' metacognition or metacognitive knowledge. In addition to exploring the relationships between learner metacognition and performance, researchers are also interested in the effects of metacognitively-oriented strategic instruction on reading comprehension (e.g., Garner, 1994, in first language contexts, and Chamot, 2005). The efforts are aimed at developing learner autonomy, independence and self-regulated learners.
Strategies for promoting metacognition include self-questioning (e.g. "What do I already know about this topic? How have I solved problems like this before?"), thinking aloud while performing a task, and making graphic representations (e.g. concept maps, flow charts, semantic webs) of one's thoughts and knowledge.