Developing a Sound Sampling Methodology © Elliott Davis Decosimo, PLLC Melody Reed, CRCM, CFSA March 9, 2015

Important Terms and Definitions Source: IIA Practice Advisory : Audit Sampling © Elliott Davis Decosimo, PLLC Audit Sampling Population Sampling Risk

Key: Validate the completeness of the population © Elliott Davis Decosimo, PLLC Know Before You Sample

Source: IIA Practice Advisory : Audit Sampling © Elliott Davis Decosimo, PLLC Types of Sampling Statistical Sampling Draw conclusions about the population based on mathematic confidence levels

Source: IIA Practice Advisory : Audit Sampling © Elliott Davis Decosimo, PLLC Types of Sampling Nonstatistical sampling AKA “Judgmental”

Source: IIA Practice Advisory : Audit Sampling © Elliott Davis Decosimo, PLLC Sampling Methods As with exercising, there are various sampling techniques

Every item in the population has an equal chance of being selected Random Sampling Source: PCAOB AU © Elliott Davis Decosimo, PLLC

Random start, select every n th Systematic Sampling Source: PCAOB AU © Elliott Davis Decosimo, PLLC N = 7

© Elliott Davis Decosimo, PLLC Haphazard Sampling Haphazard ≠ Careless Haphazard = Without Conscious Bias

Source: PCAOB AU © Elliott Davis Decosimo, PLLC Attribute Sampling Determine the characteristics of a population being evaluated a single record or document no gray area

Source: IIA Practice Advisory : Audit Sampling © Elliott Davis Decosimo, PLLC Variable Sampling Evaluate your entire population based on your sample data Mean-per-unit Ratio Difference

Source: IIA Practice Advisory : Audit Sampling & PCAOB: AU 350 © Elliott Davis Decosimo, PLLC Which Technique? Control Testing v Substantive Testing

Source: PCAOB: AU Section – © Elliott Davis Decosimo, PLLC Control Testing Relationship of the sample to the objective of the test of controls Maximum rate of deviations Allowable risk of assessing control risk Characteristics of the population (i.e. the items comprising the account balance or class of transactions of interest)

Source: PCAOB: AU Section – © Elliott Davis Decosimo, PLLC Substantive Testing Relationship of the sample to the relevant audit objective Tolerable misstatement Allowable risk of incorrect acceptance Characteristics of the population (i.e. the items comprising the account balance or class of transactions of interest)

© Elliott Davis Decosimo, PLLC OK, OK – How Many?! Answer: It Depends!

Source: The table is adapted from the table Small Population Sample Size Table in the AICPA Audit Guide Audit Sampling. The paragraph is from the AICPA Sampling Executive Summary for Posting to GAQC. © Elliott Davis Decosimo, PLLC Sample Size – Small Populations For populations between 52 and 250 items, a rule of thumb some auditors follow is to test a sample size of approximately 10 percent of the population, but the size is subject to professional judgment, which would include specific engagement risk assessment considerations.

Determine the Confidence Level (generally 95% or 90%) Determine the Tolerable Rate Population Expected Number of Deviations Sample Size Determination © Elliott Davis Decosimo, PLLC

DOCUMENTATION Most Important Thing Source: IIA Practice Advisory : Audit Sampling © Elliott Davis Decosimo, PLLC

WAKE UP © Elliott Davis Decosimo, PLLC It’s Over Now

Sources IIA Practice Advisory : Audit Sampling PCAOB: AU Section AICPA - Audit Sampling Considerations of Circular A-133 Compliance Audits Elliott Davis Decosimo ranks among the top 50 CPA firms in the U.S. With seventeen offices across seven states, the firm provides clients across a wide range of industries with smart, customized solutions. Elliott Davis Decosimo is an independent firm associated with Moore Stephens International Limited, one of the world's largest CPA firm associations with resources in every major market around the globe. For more information, please visit elliottdavis.com. © Elliott Davis Decosimo, PLLC