1. The Nomological Network

2. What Is the Nomological Net?
An idea developed by Cronbach, L. and Meehl, P. (1955). Construct Validity in Psychological Tests, Psychological Bulletin, 52, 4,
Nomological is derived from Greek and means “lawful”.
Links interrelated theoretical ideas with empirical evidence.

3. What Is the Nomological Net?
A representation

4. What Is the Nomological Net?
A representation of the concepts (constructs) of interest in a study,
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5. What Is the Nomological Net?
A representation of the concepts (constructs) of interest in a study,
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...their observable manifestations,

6. What Is the Nomological Net?
A representation of the concepts (constructs) of interest in a study,
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...their observable manifestations, and the interrelationships among and among these.

7. What Is the Nomological Net?
Theoretical Level: Concepts, Ideas
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8. What Is the Nomological Net?
Theoretical Level: Concepts, Ideas
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Observed Level: Measures, Programs

9. This interlocking system of laws is the Nomological Network.
Principles
Scientifically, to make clear what something is means to set forth the laws in which it occurs.
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This interlocking system of laws is the Nomological Network.

10. Principles The laws in a nomological network may relate...
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observable properties or quantities to each other.

11. Principles The laws in a nomological network may relate...
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different theoretical constructs to each other.

12. Principles The laws in a nomological network may relate...
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theoretical constructs to observables.

13. At least some of the laws in the network must involve observables.
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At least some of the laws in the network must involve observables.

14. Principles
"Learning more about" a theoretical construct is a matter of elaborating the nomological network in which it occurs.
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15. or of increasing the definiteness of its components.
Principles
"Learning more about" a theoretical construct is a matter of elaborating the nomological network in which it occurs...
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or of increasing the definiteness of its components.

16. Principles
The basic rule for adding a new construct or relation to a theory is that it must generate laws (nomologicals) confirmed by observation...
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17. Principles
The basic rule for adding a new construct or relation to a theory is that it must generate laws (nomologicals) confirmed by observation...
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or reduce the number of nomologicals required to predict some observables.

18. Principles
Operations that are qualitatively different "overlap" or "measure the same thing"...
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19. Principles
Operations which are qualitatively different "overlap" or "measure the same thing"...
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if their positions in the nomological net tie them to the same construct variable.

20. The Main Problem with the Nomological Net
It doesn't tell us how we can assess the construct validity in a study.