Define one family around one research decision
Suppose the decision is which of five fixed signals to carry into confirmation testing on one instrument. Register signals A through E before evaluating them on the same dated sample. For each signal j, define H0,j: its expected net excess return is at most zero, against the one-sided alternative that it is positive. Specify the benchmark, costs, return frequency, test statistic and sampling method before computing any p-values.
- A family is the set of hypotheses covered by one error-control claim. If signal thresholds, holding periods, instruments or outcome metrics were searched to reach that decision, five saved finalists do not describe the full family.
- Record code revision, parameters, symbol, timeframe, sample dates, benchmark, costs, hypothesis direction, raw p-value and decision for every evaluated candidate. Preserve failed runs with reasons; a missing result is not a p-value of zero.
- Do not split a family into convenient subgroups after seeing the results. Separate families need a defensible, prespecified interpretation, and separate 5% controls do not create a combined 5% guarantee.
- If the search history is missing or the hypotheses evolved after inspecting the same outcomes, report the limitation. Merely guessing a larger trial count does not establish the validity of adaptively selected raw p-values. Freeze the resulting hypotheses before using untouched confirmation data.