Save Your Prediction Before You Change It
Why This MattersKeep the old estimate so you can learn from what actually happened.
Keep the original estimate so you can compare it with what happened and improve the next decision without rewriting the past.
Record What You Expect
Before an important action, save the result you expect and the assumptions behind it. Afterward, it is easy to remember a success as obvious and a surprise as an exception. The original record lets you compare fairly. The purpose is to find an inaccurate input, relationship, or limit—not to label the person clever or foolish.
A story written after an event may sound convincing without showing what caused it. A side project might earn less because demand, hours, prices, costs, or delivery changed. Separate what you observed from what you still do not know. A confident explanation can otherwise take the place of checking the facts.
Find What Changed
Imagine a household expecting to build cash over six months but ending below its chosen minimum. Check whether the arithmetic was wrong or circumstances changed. A duplicate payment is an accounting error; fewer paid hours are a changed input; unexpected care costs may reveal a situation the plan left out. Similar balances can call for different corrections.
Check what happened along the way, too. A satisfactory ending can hide an earlier shortage. Keep the first shortfall, the response, and any unplanned borrowing or help in the record. Otherwise the plan may look successful only because the action that rescued it has been left out.
Change What The Evidence Calls For
Change the assumption, calculation, rule, or scope that the evidence challenges. A changed input need not invalidate the whole method. Equally, treating every failure as user error protects claims from a fair test. Sometimes a simpler process or less frequent tracking is better. Record each change and why it was made so the earlier and current versions remain clear.
Record deliberate omissions as well. An estimate might leave out taxes, emergencies, or changing work hours because the information is unavailable. If an omission later matters, you can recognize a known limit instead of inventing a surprise. Then decide whether the next estimate needs more detail or a narrower claim.
The Main Points
- Keep the original prediction and its assumptions.
- Separate arithmetic errors, changed inputs, and situations left out.
- Record the borrowing, help, or changes that affected the actual result.
Try This Small Exercise
- Save a prediction, its assumptions, and a review date.
- At review, identify the largest difference without editing the original.
- Record the change you will make and the evidence for it.