How to compare reporting periods with the right denominator
A period comparison helps make a change understandable in both absolute and relative terms. It is useful when the two periods cover comparable activity and use the same definitions.
Start with the right material.
- What you provide
- a small table displaying two explicitly labelled periods.
- The intended result
- Calculate differences with approved page code and explain them without invented causes.
How the workflow works.
Show the earlier value, later value and difference. Calculate percentage change from the earlier value, and state how zero or missing baselines are handled.
What to check in the result.
Check period length, filters and units before interpreting the result. A mathematical increase can be real while a business comparison remains misleading because the underlying windows differ.
Import the CSV with a consistent delimiter and inspect text identifiers, dates and amounts before using spreadsheet totals. Keep the original file available while checking any automatic type conversion.
Learn from the worked example.
The downloadable CSV example uses these columns: Metric, September, October, Absolute change, Percentage change. Compare a complete record with the source before sorting, combining or importing your own output.
The supplied example is illustrative. It is not a recorded run on your data.
Download the example ↓Use it with your own material.
- Open the source you want to work with and activate WebAct on that tab.
- Copy the task from the hero, add any required fields or preferences, and review the proposed actions.
- Compare the first result with your source. Ask for a specific correction or refinement where needed.