What are some differences between confirmatory analysis and exploratory analysis? In confirmatory analysis do you basically just test hypotheses? Then in exploratory analysis you try to generate hypotheses? In general, I know that you can first do exploratory analysis to form hypotheses and then confirmatory analysis to test them. But can you first do confirmatory analysis and then do exploratory analysis?
 A: First EDA will be done on the data set to understand the data & prepare the hypothesis, then confirmatory analysis is done. In EDA, most of the time we do visual analysis. Whereas in Confirmatory analysis we take probability models into consideration.
Comparison from here:


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*Confirmatory Analysis


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*Inferential Statistics - Deductive Approach


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*Heavy reliance on probability models

*Must accept untestable assumptions

*Look for definite answers to specific questions

*Emphasis on numerical calculations

*Hypotheses determined at outset

*Hypothesis tests and formal confidence interval estimation


*Advantages


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*Provide precise information in the right circumstances

*Well-established theory and methods


*Disadvantages


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*Misleading impression of precision in less than ideal circumstances

*Analysis driven by preconceived ideas

*Difficult to notice unexpected results



*Exploratory Analysis


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*Descriptive Statistics - Inductive Approach


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*Look for flexible ways to examine data without preconceptions

*Attempt to evaluate validity of assumptions

*Heavy reliance on graphical displays

*Let data suggest questions

*Focus on indications and approximate error magnitudes


*Advantages


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*Flexible ways to generate hypotheses

*More realistic statements of accuracy

*Does not require more than data can support

*Promotes deeper understanding of processes

*Statistical learning


*Disadvantages


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*Usually does not provide definitive answers

*Difficult to avoid optimistic bias produced by overfitting

*Requires judgement and artistry - can't be cookbooked




For further reading read this.
A: I don't think there is a set recipe for when to perform which.  You have to use the tools required for the task, whether they are most useful for an exploratory analysis or testing hypotheses.  It is likely you will begin with hypotheses (that's why you collected this data in the first place right?) and then test them.  Your results may not be what you expect.  Then you go back to exploring the data and generate new hypotheses.  This is just how the scientific method works.  
