•Internal
•External
•Construct
•Statistical Conclusion
•Internal: Informative variable missing. Bring data from other sources
•External: Fixation variable make the result perfect. Model may not generalize
•Construct: Class imbalance affects outcome badly
•Statistical Conclusion: Based on the statistical measure used, the conclusion can be incorrect.
•Data Mining: Association: Support, Confidence, and Lift
Internal Validity
Is your experiment (and Model) Internally Valid?
What is the Threat that
the experiment (model, and outcome) is invalid (internally)?)
Example: Reasons that inferences between two variables are causal are incorrect. [b]
Cause: Lack of informative variables
Solution: Bring data from other sources


External Validity
Is your experiment (and Model) Externally Valid?
What is the Threat to external Validity that the experiment (model, and outcome) is externally invalid?)
“Study results may not apply to other groups.”
Cause: Fixation Variable
Solution: exclude fixation variable from the study


Ref: https://en.wikipedia.org/wiki/External_validity
Construct Validity
Is your experiment (and Model) Valid by Construction?
What is the Threat that the experiment (model, and outcome) is invalid by Construction?)
Example: in Classification if the data is imbalanced,
Variables’ effect on the outcome can be invalid
Cause: Construction/balance problem
Solution: Treat Data for Imbalance
Statistical Conclusion Validity
Is your conclusion (from the experiment and the Model) Statistically Valid, even done by Statistical Analysis?
What is the Threat that the conclusion (from the experiment and the Model) is invalid?)
Example: In data mining, you just considered Association. But that does not give the full picture
Solution: Include Support, Confidence, and Lift

Ref: https://www.analyticsvidhya.com/
Data Analytics, Machine Learning.
Data Analytics, Machine Learning, Data Science