ACCA Applied Knowledge · Management Accounting
Sampling Methods for ACCA Management Accounting
Sampling means studying a selected part of a population to draw conclusions about the whole. In ACCA MA you must identify the method (random or non-random), know how it works, and state its advantages and disadvantages. Match the scenario wording to the method's definition to answer quickly.
What this chapter covers
This chapter covers how a business collects information without examining every item. You start with the population (everything you want to know about), the sampling frame (the list you pick from) and the reasons for sampling: it saves time and cost, and sometimes testing destroys the item.
You then learn two families of methods. Random (probability) sampling gives every item in the population a known chance of selection. It includes simple random, systematic, stratified, cluster and multistage sampling. Non-random sampling includes quota, judgemental (purposive) and convenience sampling. The exam asks you to recognise each method from a short description and to judge when it suits.
Sampling is part of the MA syllabus on information and data collection. It links to how managers gather cost, sales and performance data, and how they judge whether that data is reliable. Sampling can be examined in objective test questions and could also feature in multi-task questions, so learn the methods well enough to apply them to a scenario.
Sampling questions are often definition-based, so they can be quick marks if you know the methods. Once you can tell the methods apart and recall one or two strengths and weaknesses of each, you can answer a two-mark objective test question in under a minute. That leaves more time for the calculation questions in Section A and the ten-mark multi-task questions in Section B. The ideas also help you judge whether data used in budgeting and performance measurement is reliable.
Sampling methods: topics in the order to study them
- 1Population, Sampling Frame and Why We SampleYou need the basic terms first, because every method is described using population and sampling frame.
- 2Random Sampling MethodsThese are the core methods with clear rules, and you need them before you can contrast them with non-random ones.
- 3Non-Random Sampling MethodsEasier to learn once you know random methods, because the key difference is whether selection chances are known.
- 4Advantages and Disadvantages of Sampling MethodsThis pulls all methods together, so you can compare them and choose the best fit for a scenario.
How to prepare Sampling methods
This chapter is mostly definitions and comparisons, so your preparation should focus on recognition and quick recall rather than long calculations.
- Write the definitions of population, sampling frame and sample in your own words, and say why a business would sample instead of counting everything.
- Learn each random method with a one-line rule: simple random (every item equal chance), systematic (every nth item after a random start), stratified (split into groups, sample each), cluster (select whole groups), multistage (sample in stages).
- Learn each non-random method with a one-line rule: quota (fill set numbers by category), judgemental (chosen by an expert's view), convenience (whatever is easiest to reach).
- Build a comparison sheet with one strength and one weakness per method. Focus on bias, cost, speed and need for a sampling frame.
- Practise spotting the method from short scenarios. Underline the clue words, such as 'every tenth', 'groups', 'whoever was available' or 'quota'.
- Do objective-test practice and review every wrong answer by naming the clue you missed.
- On the last day, recite the list of methods and their one-line rules without notes.
Common mistakes in Sampling methods
Confusing stratified sampling with quota sampling
Fix: Ask how items are picked inside each group. Random selection means stratified. Interviewer's choice until the quota is filled means quota.
Mixing up systematic and simple random sampling
Fix: If the question says every nth item, it is systematic. Only the starting point is random.
Confusing the population with the sampling frame
Fix: The population is everyone or everything of interest. The frame is the actual list you can select from, and it may be incomplete.
Saying non-random sampling is always poor
Fix: Say it is quicker and cheaper and needs no full frame, but it risks bias. Choose by what the scenario needs.
Mixing up cluster and stratified sampling
Fix: Stratified samples from every group. Cluster selects some groups and covers those groups entirely.
Choosing an answer by recognising a familiar word instead of reading the full scenario
Fix: Read the whole description, find the clue about how items were chosen, then rule out options one by one.
Last-day revision: Sampling methods
- The population is the whole group you want information about.
- The sampling frame is the list of items from which the sample is drawn.
- Sampling saves time and cost and is needed when testing destroys the item.
- Random sampling gives every item a known chance of selection.
- Simple random sampling needs a full sampling frame, such as a numbered list.
- Systematic sampling picks every nth item after a random start.
- Stratified sampling splits the population into groups and samples each group.
- Cluster sampling selects whole groups, which cuts cost but can be less representative.
- Quota sampling fills set numbers per category, but selection is not random.
- Judgemental sampling relies on a person's view, so it can be biased.
- Convenience sampling is quick and cheap but is the most likely to be unrepresentative.
- Non-random methods do not let you measure sampling error reliably.
Sampling methods practice questions
- A survey of 200 customers uses quotas: 50% aged under 40 and 50% aged 40 or over. Interviewers reach the quotas, but they tend to approach c…
- A cost accountant selects every 20th invoice from a filing system in which invoices are stored in batches of 20, each batch beginning with a…
- A cost accountant needs to know the average time taken to inspect each unit in a batch, where inspection involves destroying the unit being …
- A firm wants to estimate the proportion of invoices containing errors. Its population is all 12,000 invoices issued in the year, but the sam…
- A company holds 2,000 numbered purchase invoices and wants to select a sample of 50 so that every invoice has an equal chance of selection, …
- A factory employs 600 staff: 300 machine operators, 200 assemblers and 100 supervisors. A stratified random sample of 60 employees is to be …
- A firm has 10,000 employees: 8,000 in production and 2,000 in administration. It wants views on a new bonus scheme from both groups. Which i…
- Which of the following is a recognised disadvantage of quota sampling compared with simple random sampling?
Sampling methods in other exams
The same ground in other exams, if you are preparing for more than one or want another angle on it.
Sampling methods: frequently asked questions
What is the difference between random and non-random sampling?
In random sampling every item has a known chance of being chosen. In non-random sampling selection depends on judgement, quotas or convenience, so chances are unknown. Random methods allow better control of bias.
Is sampling a calculation topic in ACCA MA?
Mostly no. Questions are most likely to be about recognising methods and knowing their advantages and disadvantages. You rarely need long working, which makes it quick to revise.
Which sampling method is best?
There is no single best method. Pick the one that fits the situation, balancing cost, time, accuracy and whether you have a full sampling frame.
How are sampling questions asked in the exam?
Sampling is most likely tested through objective test questions, which in MA are two marks each in Section A, often multiple choice or multiple response. It could also appear within a multi-task question. You may be given a short scenario and asked to name the method or choose a correct statement.