What is the difference between nonstatistical sampling and statistical sampling?
Statistical sampling:
Nonstatistical sampling:
When is professional judgment necessary in the use of statistical or nonstatistical sampling by an auditor?
The auditor must use professional judgment to:
Define sampling risk.
Sampling risk is the risk that the auditor’s conclusion based on a sample is different from the conclusion that would have been reached if the tests had been applied to all items in the population.
Define the two aspects of sampling risk for tests of controls.
Risk of assessing control risk too low:
Deciding the control is more effective/reliable than it really is; affects audit effectiveness.
Risk of assessing control risk too high:
Deciding the control is less effective/reliable than it really is; affect audit efficiency.
Identify two aspects of sampling risk that the auditor should be concerned with when performing substantive testing.
Risk of incorrect acceptance:
Deciding from the sample that the balance is correct when it is really materially misstated; affects audit effectiveness.
Risk of incorrect rejection:
Deciding from the sample that the balance is materially misstated when it is really correct; affects audit efficiency.
What is the relationship between sampling risk and reliabilty (confidence level)?
Sampling risk + Confidence level = 100%
What is attribute sampling?
Attribute sampling is a statistical sampling method used to estimate a rate of occurrence in a sample. It is used in tests of controls.
Define tolerable deviation rate (for attribute sampling) and tolerable misstatement (for variable sampling).
What factors affect sample size for an attribute sampling application?
The following factors affect sample size in an attribute sampling application:
What rates are compared in drawing a conclusion about an attribute sampling application?
The auditor compares the upper deviation rate to the tolerable deviation rate in drawing conclusions about an attribute sampling application. If the upper deviation rate exceeds the auditor’s tolerable deviation rate, the auditor will not rely on the control. (The upper deviation rate is the sample deviation rate plus an allowance for sampling risk.)
What factors affect sample size for a variables sampling application?
The following factors affect sample size in a variables sampling application:
Describe variables sampling.
Variables sampling is a statistical sampling method used to estimate the numerical amount of a population. Variable sampling is used primarily in substantive testing.
What is stratification and why would an auditor stratify a population?
Stratification separates the sample into relatively homogenous groups. Each group is treated as a separate population.
Stratification is typically used when a population has highly variable amounts. Stratification usually results in a smaller sample size.
What amounts are compared in drawing a conclusion about a variables sampling application?
The auditor compares the client’s book value to the calculated range in variables sampling application. If the recorded book value is with in the acceptable range, the book value is considered fairly stated. (The calculated range is the point estimate, as determined from the sample, plus/minus an allowance for sampling risk.)
What is discovery sampling?
Discovery sampling is a type of attribute sampling used when the expected deviation rate is zero or near zero. It is used when the auditor is looking for a very critical characteristic (e.g., fraud).
What are the sampling plans commonly used for variables estimation?
Define Probability-Proportional-to-Size (PPS) sampling.
Probability-Proportional-to-Size (PPS) sampling is a hybrid sampling technique that uses attribute sampling theory to express a conclusion in dollar amounts rather than as a rate of occurrence. The sampling unit is defined as an individual dollar in a population, which creates the effect of stratified sampling (the unit’s chance of being selected increases as its amount increases).
What are the advantages and disadvantages of using PPS sampling?
Advantages:
Disadvantages:
How is the sampling interval determined in a PPS sampling application?
Sampling interval =
Tolerable misstatement
Reliability factor
(The reliability factor comes from a table and is based on the risk of incorrect acceptance.)
How is the sample size determined in a PPS sampling application?
Sample size =
Recorded amount of the population
Sampling interval
What is a control deficiency?
A control deficiency exists when the design or operation of a control does not allow management or employees, in the normal course of performing their assigned functions, to prevent or detect/correct misstatements on a timely basis.
What is a significant deficiency?
A significant deficiency is a deficiency, or a combination of deficiencies, in internal control over financial reporting that is less severe than a material weakness, yet important enough to merit the attention of those charges with governance (responsible for oversight of the company’s financial reporting).
What is a material weakness?
A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the company’s annual or interim financial statements will not be prevented or detected/corrected on a timely basis.
What is the auditor’s responsibility with respect to control deficiencies identified during a financial statement audit of a nonissuer?