Definition

Definition is a useful method for specifying the basic nature of any phenomenon, concept, idea or thing. Does your tutor have a "sense of humour" or "charisma" depends on establishing a clearly defined, commonly agreed-upon meaning for these terms. No matter what discipline your are specialising in you will need to define concepts or redefine old ones as the results of new research becomes known.

We will begin by asking: "what is a concept?" .
1) A concept is a category.
2) A concept is a definition.

Statement 1 indicates that to have a concept is to be able to group things with common characteristics into a category. Statement 2 indicates that a definition is a means one uses in deciding how to group things with common characteristics.
Another way to think about the meaning of a concept is to imagine that a box is a category and that the box includes everything that is part of the concept "X".


Everything that is not concept "X" (the non-instances of the concept) belongs outside the box; everything that is concept "X" (the instances of the concept) belongs inside the box.
Thus the content of the box is what concept "X" is all about.

By learning a concept we are able to discriminate instances from non-instances.

The choice of definitions for central concepts is extremely important in any area of scientific study, and the field of focus amounts in a decision to study those aspects that fall under the definition and to ignore aspects excluded by the definition.

Dr.J Morley's phraseology;

General meanings or application of meanings
The term X refers to ��_
The term X encompasses A), B), and C).
X can be defined as ��_ It encompasses ��_
X can be loosely described as a correlation.
The term X has come to be used to refer to ��_
The term X is generally understood to mean ��_
The term X has been applied to situations where students ��_
In the literature, the term tends to be used to refer to ��_
The broad use of the term X is sometimes equated with ��_
Whereas X refers to the operations of ��_, Y refers to the ��_
The term disease refers to a biological event characterised by ��_
The term X is a relatively new name for a Y, commonly referred to��_
In broad biological terms, X can be defined as any stimulus that is ��_
Defined as XYZ, obesity is now considered a worldwide epidemic and is associated with ��_

Indicating difficulties in defining a term
A generally accepted definition of X is lacking.
Unfortunately, X remains a poorly defined term.
The term X embodies a multitude of concepts which ��_
A further definition is given by Smith (1982) who describes ��_
In the field of language teaching, various definitions of X are found.
Smith (2001) identified four abilities that might be subsumed under the term X: a) ��_
Although differences of opinion still exist, there appears to be some agreement that X refers to ��_
X is a commonly-used notion in language learning and yet it is a concept difficult to define precisely.

Specifying terms that are used in an essay or thesis
The term X will be used solely when referring to ��_
In the present report, X was therefore defined in terms of ��_
In this essay, the term X will be used in its broadest sense to refer to all ��_
In this paper, the term that will be used to describe this phenomenon is X.
In this dissertation, the terms X and Y are used interchangeably to mean ��_
Throughout this thesis, the term education is used to refer to informal systems as well as ��_
While a variety of definitions of the term X have been suggested, this paper will use the definition first suggested by Smith (1968) who saw it as ��_

Referring to people�۪s definitions: author prominent
For Smith (2001), fluency means/refers to ��_
Smith (2001) uses the term ���fluency�۪ to refer to ��_
Smith (1954) was apparently the first to use the term ��_
The term ���fluency�۪ is used by Smith (2001) to refer to ��_
Macro-stabilisation policy is defined by Smith (2003: 119) as �����_ ��_�۪
This definition is close to those of Smith (2012) and Jones (2013) who define X as ��_
In 1987, sports psychologist John Smith popularized the term ���X�۪ to describe ��_
According to a definition provided by Smith (2001:23), fluency is ���the maximally ��_
Aristotle defines the imagination as ���the movement which results upon an actual sensation.�۪
One of the first people to define nursing was Florence Nightingale (1860), who wrote: �����_ ��_�۪
Chomsky writes that a grammar is a ���device of some sort for producing the ��_.�۪ (1957, p.11).
Smith, has shown that, as late as 1920, Jones was using the term ���X�۪ to refer to particular ��_
The term ���matter�۪ is used by Aristotle in four overlapping senses. First, it is the underlying ��_ Secondly, it is the potential which ��_
Smith et al. (2002) have provided a new definition of health: ���health is a state of being with physical, cultural, psychological ��_�۪

Referring to people�۪s definitions: author non-prominent
Validity is the degree to which an assessment process or device measures what it is intended to measure (Smith et al., 1986).

Commenting on a definition
This definition includes ��_
allows for ��_
highlights the ��_
helps distinguish ��_
takes into account ��_
poses a problem for ��_
will continue to evolve.
can vary depending on ��_
was agreed upon after ��_
has been broadened to include ��_
The following definition is intended to ��_
modelled on ��_
too simplistic:
useful because ��_
problematic as ��_
inadequate since ��_
in need of revision since ��_
important for what it excludes.
the most precise produced so far.