Description

The PrePostNEGD.summary() method (in experiments/prepostnegd.py) currently prints only the formula, causal impact summary stat, and model coefficients. There was a TODO indicating that additional experiment-specific outputs could be added.

Proposed solution

Determine what additional information would be useful in the summary output. Candidates include:

• Group-level means (pre/post, treatment/control)
• Sample sizes per group
• Effect size measures

Context

Triaged from #666. The TODO was removed as it was too vague to be actionable in-place.