AU 14 - Sampling Flashcards
3 methods of selecting for testing?
- selecting all items
- selecting specific items
- audit sampling
When is it appropriate to use all items?
- population consists of small number of large-value items
- there is sig risk, and other means do not provide appropriate evidence
- repetitive nature of automated systems makes this cost-effective.
What specific items may be counted? Does this constitute audit sampling?
- high value or key items
- all items over a certain amount
- items to obtain information
NO, it does not constitute sampling and can’t be extrapolated to the general population
Reasons for using audit sampling
- can be costly to test 100% of population
- can be time consuming to test 100% of population
- nature and materiality of account does not need 100% to be tested
- practitioner only required to obtain reasonable assurance, not absolute so less testing required
What is sampling risk?
Risk that the conclusions drawn from the sample may not be extrapolated to whole population
What is a deviation? And a misstatement?
Deviation occurs when controls not performing as it was designed. Misstatement occurs when reported amount differs from actual amount determined when applying audit procedure.
3 considerations of population characteristics
- is sample representative of the population?
- is population complete?
- what is expected deviation or misstatement rate?
3 ways of stratifying a population
- monetary value
- identifying characteristics
- representative items
Formula for calculating sample error rate
Total misstatements discovered in sample items / Total book value of representative items tested x Book value of representative item population
Statistical sampling approach
- random selection of sample items
- use of probability theory to evaluate sample results, including measurement of sampling risk
Statistical sampling +/-
+ objective and defensible
+ provides a way of estimation of sample size
+ allows an estimate of the sampling risk and error of entire population
- more work involved
- audit staff involved may need more training
Non-stat sampling +/-
+ takes less time
+ less expensive
- cannot draw statistical inference
- based upon professional judgment so more open to scrutiny
5 types of sample selection techniques
random selection
systematic selection
monetary unit sampling
haphazard selection
block selection
Sample evaluation answers which two questions
- was sufficient appropriate audit evidence obtained?
- are there material errors in the population?