Chapter 5 Flashcards
What is the difference between nonstatistical and statistical sampling?
Statistical sampling
- Uses laws of probability for selection and evaluation of a sample
- Allows for quantification of audit risk and sufficiency of audit evidence’
Nonstatistical sampling:
- Does not utilize statistical models in calculations
- Audiors use their judgment to determine sample sized to evaluate the selected samples
When is professional judgment necessary in theuse of statistical or nonstatistical sampling by an auditor?
The audior must use professional judgment to:
- Define the population and sampling unit
- Select the appropriate sampling method
- Evaluate whether the audit evidence is appropriate
- Evaluate the nature of deviations or errors
- Consider sampling risk
- Evaluate sample results and project to the population
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 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 asessing control risk too high:
- Deciding the control is less effective/reliable that it really is; affects audit efficieny
Identify two aspects of sampling risk that the auditor would 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 reliability (confidence level)?
Sampling Risk
+
Confidence Level
=
100%
What is attribute sampling?
Attribute sampling is a statistical sampling method used to estimate a rate of occurence in a sample. It is used in tests of controls
Define tolerable deviation rate (for attribute sampling) and tolerable misstatement (for variables sampling).
Tolerable deviation rate: The maximum rate (%) of deviation from a control procedure that the auditor is willing to accept while still relying on the control
Tolerable misstatement: The largest amount of misstatement the auditor believes can exist in a balance or class of transactions without causing the F/S to be materially misstated.
What factors affect sampliing size for an attribute sampling application?
The following factors affect sample size in an attribute sampling application:
- Risk of assesing control risk too low (inverse relationship)
- Tolerable deviation rate (inverse relationship)
- Expected deviation rate (direct relationship)
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 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:
- Standard deviation or population variability (direct relationship)
- Tolerable misstatement (inverse relationship)
- Acceptable level of risk (inverse relationship)
- Expected size and frequency of misstatements (direct relationship)
- Assesed level of risk (direct relationship)
Describe variables sampling
Variables sampling is a statistical sampling method used to estimate the numerical amount of a population. It may be used to substantiate management’s assertions in the F/S by determining whether amounts are reasonable. Often, this is accomplished by developing independent estimates of F/S amounts. Variable sampling is used primarily in substantive testing.
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 a variables sampling application. If the recorded book value is within the acceptable range, the book value is considered fairly stated. (The calculated range is the point estimate, as determine 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
What are the sampling plans commonly used for variables estimation?
- Mean-per-unit estimation: The sample mean is multiplied by the number of items in the population to estimate population value
- Ratio estimation: The ratio between book value and audited value (from a sample) is used to estimate population value
- Difference estimation: The difference between book value and audited value (from a sample) is used to estimate population value