Lim Wei Ming ·

Sampling fifty files without pretending you read the book

How we draw a sample for a branch or a producer panel so the findings memo is honest about what it can and cannot say.

Small group in an office discussing papers around a table

A compliance officer once asked us to ‘just look at everything from Kajang for Q1’. That was 1,100 motor and medical cards. We declined the ‘everything’ and offered a sample. The sample still changed how that branch checked declarations.

Fifty files is a common size because it is large enough to show a habit and small enough to read. We mix a random draw with a short list of files you already distrust. If the random draw is clean and the distrust list is not, that is a finding about targeting, not about the branch as a whole. We say so.

What a sample cannot do is certify that the other 1,050 files are fine. We will not write a sentence that sounds like it does. The engagement letter states the population, the sample size, and the period. The memo repeats those limits at the top so a later reader does not stretch the work.

If Bank Negara Malaysia or an internal auditor later asks what was covered, you will have a one-page description that matches what we actually opened.

All working notes