The Nomological Network
What Is the Nomological Net?
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An idea developed by Cronbach, L. and
Meehl, P. (1955). Construct Validity in
Psychological Tests, Psychological
Bulletin, 52, 4, 281-302.
Nomological is derived from Greek and
means “lawful”.
Links interrelated theoretical ideas with
empirical evidence.
What Is the Nomological Net?
A representation
What Is the Nomological Net?
A representation of the concepts (constructs) of
interest in a study,
Construct
Construct
Construct
Construct
Construct
What Is the Nomological Net?
A representation of the concepts (constructs) of
interest in a study,
Construct
Obs
Obs
Construct
Construct
Construct
Construct
Obs
Obs
Obs
Obs
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...their observable manifestations,
Obs
Obs
What Is the Nomological Net?
A representation of the concepts (constructs) of
interest in a study,
construct
Obs
Obs
construct
construct
construct
construct
Obs
Obs
Obs
Obs
Obs
Obs
Obs
Obs
...their observable manifestations, and the
interrelationships among and among these.
What Is the Nomological Net?
Theoretical Level: Concepts, Ideas
Construct
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Construct
Construct
Construct
Construct
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What Is the Nomological Net?
Theoretical Level: Concepts, Ideas
Construct
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Construct
Construct
Construct
Construct
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Obs
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Observed Level: Measures, Programs
Principles
Scientifically, to make clear what something is
means to set forth the laws in which it occurs.
Construct
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Construct
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This interlocking system of laws is the
Nomological Network.
Obs
Principles
The laws in a nomological network may relate...
Construct
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Construct
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Construct
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observable properties or quantities to each other.
Principles
The laws in a nomological network may relate...
Construct
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Construct
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Construct
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different theoretical constructs to each other.
Principles
The laws in a nomological network may relate...
Construct
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Construct
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Construct
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theoretical constructs to observables.
Obs
Principles
Construct
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Construct
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Construct
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At least some of the laws in the network
must involve observables.
Principles
"Learning more about" a theoretical construct is a matter of
elaborating the nomological network in which it occurs.
Construct
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Construct
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Principles
"Learning more about" a theoretical construct is a matter of
elaborating the nomological network in which it occurs...
Construct
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Construct
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Construct
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or of increasing the definiteness of
its components.
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Principles
The basic rule for adding a new construct or relation
to a theory is that it must generate laws
(nomologicals) confirmed by observation...
Construct
Construct
Construct
Construct
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Principles
The basic rule for adding a new construct or relation
to a theory is that it must generate laws
(nomologicals) confirmed by observation...
Construct
Construct
Construct
Construct
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or reduce the number of nomologicals
required to predict some observables.
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Principles
Operations that are qualitatively different
"overlap" or "measure the same thing"...
Construct
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Construct
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Construct
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Principles
Operations which are qualitatively different
"overlap" or "measure the same thing"...
Construct
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Construct
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if their positions in the nomological net tie them to
the same construct variable.
The Main Problem with the
Nomological Net
It doesn't tell us how we can
assess the construct
validity in a study.