After the kick-off word, the rest of the definition should The kick express how the concept being defined is some special case or variation of the more general concept represented by the kick-off word. In other words, the rest should focus on the essence of the differentiation. For example, responsible for the conduct of games and for order on the playing field expresses the essence of what makes umpires distinct from other league representatives.
Digging Deeper: In classical logic, called genus The kick (or family), and the rest of the definition differentia — fancier terms, but the same ideas.
It can be helpful in defining a concept to see yourself as specifying what qualifies a thing to be an instance of the concept. For example, each instance of umpire must conform to the concept’s definition. If something or somebody does not conform, then that something is not an instance of umpire. It cannot be classified that way. Fundamentally, definitions are about proper classification of things.
Defining Similar Things
To classify things that are not very alike, definitions can be phone number lead somewhat lax and still suffice. Not so as things become increasingly similar. Then fine distinctions must be made.
In residential housing, for example, consider the three concepts condo, townhouse, and co-op. Each is a housing unit. Unlike a standalone housing unit, a condo, townhome, or co-op is part of a multi-unit complex. Clearly, the three concepts are similar to each other, but how are they different? What are the most significant aspects of differentiation?
You are likely to discover two
(1) legal ownership and (2) physical configuration. (These may overlap.) Definitions should be drafted, focusing on these two aspects, then iteratively refined until adequately distinguished. The following are candidate definitions with embedded numbers (for illustration only) to indicate the two aspects for each case.