Body of Knowledge : Guidelines for Creating Good Definitions

Created and last modified by sara.acton on Aug 17, 2015

In this page, we will motivate the creation of good definitions, describe what makes a good definition, and outline some helpful steps for creating good definitions.

Motivating good definitions: Why do we care?

Good definitions are well worth the effort. In fact, they are central to the effort of data governance, and creating and approving them is one of the major tasks for data governance teams. A good definition, once developed, provides a clear picture of what the data asset is (and, by extension, what it isn't). A good definition precludes the kinds of contradictions and ambiguities that create problems for the interpretation and organization of data, especially large amounts of data across numerous databases.

Characteristics of good definitions

Good definitions are:

  • Specific and disambiguating
  • Concise
  • Accessible to the full breadth of the target audience

(info) Philosopher H. Paul Grice wrote extensively about how to package information for successful communication. You could say that good definitions follow his Maxims of Conversation.1 Read a summary here.

Specific and disambiguating

A good definition, especially for the purposes of data governance, most crucially picks out the central identifying characteristic(s) of an asset (specific), which include the characteristic(s) that set(s) that asset apart from others (disambiguating).

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Example: Defining "Capital Budget"

Weak Definition: A capital budget is a type of budget

  • This definition also applies to all other budgets, including annual budgets, non-base budgets, and overhead budgets. The definition is not specific enough and does not disambiguate capital budgets from other budgets.

Stronger Definition: A capital budget is a long-term plan for the allocation of funds for non-recurring expenditures in the company.

  • This definition does not apply to annual budgets, as it is defined as a long-term budget. However, both non-base budgets and capital budgets can be defined as "non-recurring expenditures" in a company; a non-base budget more typically is allocated for a project or to a department, while a capital budget is used to procure new assets that help the company grow.

Good Definition: A capital budget is a long-term plan for the allocation of funds to be invested in assets that support growth and add to the company's net worth.

Concise

A good definition is as brief as possible, while still being specific and disambiguating. In other words, a good definition cuts out all text that does not contribute to the unambiguous identification of an asset.

(info) See below, #Helpful steps for creating good definitions, for how to identify text to cut out of a definition.

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Example: Defining "Capital Budget"

Weak Definition: A capital budget (that is, an estimate of income and expenditures over a predetermined period of time) is a long-term plan for the allocation of funds to be invested in assets such as machinery, land, or stocks and bonds, that support growth and development and add to the company's net worth.

  • This definition is specific and disambiguating in that it cannot be applied to any other kinds of budgets.
  • However, unnecessary text, such as the nested definition of a budget, repetitive words, and the list of types of capital do not assist in identifying a capital budget from a set of budgets.

Good Definition: A capital budget is a long-term plan for the allocation of funds to be invested in assets that support growth and add to the company's net worth.

Accessible to the full breadth of the target audience

A good definition can be read and understood with ease by any user. Good definitions are written such that their meaning is easily grasped by a naive educated reader (e.g., an external consultant unfamiliar with project specifics). Including all readers extends the reach and power of the definition.

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Example: Defining "Capital Budget"

Weak Definition: A capital budget is a long-term plan for the apportionment of pecuniary investments in assets that buttress growth and exert an augmentative effect on net worth.

  • This definition makes all of the same points in our good definition, but in an obscure and unnecessarily technical way.

Good Definition: A capital budget is a long-term plan for the allocation of funds to be invested in assets that support growth and add to the company's net worth.

Helpful steps for creating good definitions

In this section, we'll go over a few different skills for definition writing, including things to do and things to avoid.

Things to do

Seek out unique characteristic(s)

When writing a definition, consider the asset to be defined and ask yourself, what is it that makes this unique from other similar assets? This characteristic or set of characteristics should be central to your definition.

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Example: Defining "Capital budget"

Characteristics that differentiate capital budgets from other kinds of budgets:

    • Long-term (differs from annual budget)
    • Intended to be invested in the company for income generation (differs from operational budget)
    • Allocated for non-fixed, non-recurring expenses (differs from overhead budget)
    • Company-wide (differs from divisional budget)
    • Not necessarily project-specific (differs from non-base budget)

Write true and relevant definitions

If a definition is false, it is worse that useless: it is also misguiding. Errors happen, sometimes through typos and sometimes because of a lack of information. In both cases, false definitions can be caught by asking many people to read over a definition in order to approve it. This is why definition approval and data quality management are central to data governance!

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Example: Defining "Capital Budget"

Weak Definition: A capital budget is a long-term plan for the allocation of funds for the payment of salaries.

  • Salaries do not fall under the category of capital, and this definition is false.

Use phrases like "is a", "has a", and "used for"

Definitions are stronger when they identify the type or class of the asset ("is a"), provide central identifying characteristics of the asset ("has a"), and note the general function of the asset ("used for").

(info) For more, see Stanford University Data Stewardship's Data Definitions Best Practices.2

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Example: Defining "Capital Budget"

A capital budget is a long-term plan for the allocation of funds to be used for investment in assets that have a positive effect on company growth and add to the company's net worth.

Things to avoid

Nested definitions

When writing a definition, do not include nested definitions (definitions within a definition). This adds unnecessary complexity to the definition.

(info) Collibra's Hyperlinking feature provides an easy alternative: a link to another defined asset provides readers with a simple way to learn more about an unknown term within a definition.

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Example: Defining "Customer Identifier"

A customer identifier is a unique token that identifies a customer (that is, a person or organization that placed at least one order for at least one product).

Rewrite:

A customer identifier is a unique token that identifies a customer (that is, a person or organization that placed at least one order for at least one product).

Lists

The purpose of a definition is to pinpoint the meaning of a concept, not to provide every possible example of that concept. Lists of examples should be avoided, as should lists of descriptors, unless they are key to a specific and unambiguous definition.

(info) If the listed examples are also assets, they can be linked to the defined asset using a relation. See Relation Types.

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Example: Defining "Customer"

A customer, such as a department store customer, a convenience store customer, or a conglomerate customer, is a person or organization that has placed at least one order for at least one product, such as home essentials, beauty products, or landscaping tools.

Rewrite:

 A customer, such as a department store customer, a convenience store customer, or a conglomerate customer, is a person or organization that has placed at least one order for at least one product, such as home essentials, beauty products, or landscaping tools.

Using a synonym as a definition

A definition should describe an asset. Synonyms do not describe the characteristics of an asset, but only provide another name for that asset. This is not a definition.

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Example: Defining "Employee"

An employee is a worker.

Rewrite:

An employee is an individual who holds a contract of employment with a company and receives remuneration for performing an identified set of duties per the terms of the contract.

Circular definitions

A definition should not include the name of the asset in the definition. Importantly to the development of a business semantics glossary or other repository of definitions, two assets should not be defined in such a way that each refers to the other for its definition. Instead, look for the unique characteristics of the asset and use those to define it.

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Example: Defining "Customer Date of Birth"

The customer date of birth is the birth date of a customer.

Rewrite:

The customer date of birth is the calendar day on which the customer was born.

Obscure or overly technical language

Definitions that rely on technical language or make assumptions about a reader's knowledge base should be avoided. Wherever possible, replace technical language or jargon with simple explanations.

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Example: Defining "Capital Budget"

A capital budget is a long-term plan for the apportionment of pecuniary investments in assets that buttress growth and exert an augmentative effect on net worth.

  • Many parts of this definition could be simplified, helping it to become both more concise and more accessible.
    • apportionment --> allocation
    • pecuniary --> monetary
    • buttress growth --> support growth
    • augmentative effect --> increase


1 Grice, H. Paul (1975). "Logic and conversation". In Cole, P. and Morgan, J. Syntax and semantics. 3: Speech acts. New York: Academic Press. pp. 41–58.
2 Stanford University Data Stewardship website: http://dg.stanford.edu