Primary vs secondary, quantitative vs qualitative, sampling methods
🔬 Research methods⏱ 18 min📝 3 practice questions
Learning Objectives
By the end of this lesson you will be able to…
Explain the purpose of market research and why businesses conduct it
Distinguish between primary and secondary research with examples
Compare quantitative and qualitative data and their uses
Evaluate different sampling methods — random, stratified, quota
Assess the reliability and limitations of different research methods
Why It Matters
Purpose of Market Research
Definition
Market research is the process of collecting and analysing data about customers, competitors and market conditions to help businesses make informed decisions.
Identify customer needs: What do people want? What problems do they need solved?
Reduce risk: Launching a new product without research risks expensive failure (e.g. Google Glass, New Coke)
Understand the market: Market size, trends, competitor strengths and weaknesses
Target marketing: Identify the most profitable customer segments to focus on
Research Type 1
Primary Research
Definition
Primary (field) research is data collected first-hand for a specific purpose. It didn't exist before the business collected it.
Trials / pilots — testing a product with a sample group
Advantages & Disadvantages
✓ Up to date and specific to the business
✓ Can ask exactly the right questions
✓ Can be kept confidential from competitors
✗ Expensive and time-consuming to collect
✗ Small samples may not be representative
✗ Respondents may give biased or dishonest answers
Research Type 2
Secondary Research
Definition
Secondary (desk) research uses data that already exists, collected by someone else for a different purpose.
Sources
Government statistics (ONS, trade data)
Industry reports (Mintel, Euromonitor)
Newspaper and magazine articles
Competitors' published accounts
Internet searches and social media data
Internal records (own sales data)
Advantages & Disadvantages
✓ Cheap and quick to access
✓ Large datasets available
✓ Good for understanding broad trends
✗ May be out of date
✗ Not specific to this business's question
✗ Competitors can access the same data
Types of Data
Quantitative vs Qualitative Data
Quantitative data
Numerical data that can be measured and analysed statistically.
"72% of respondents preferred the new packaging"
"Average spend per customer: £24.60"
Sales figures, market share percentages
Collected via: closed surveys, sales records
✓ Easy to compare and present in charts ✗ Doesn't explain the reasons behind results
Qualitative data
Non-numerical data about opinions, feelings and attitudes.
"I chose this brand because it feels premium"
"The instructions were confusing and frustrating"
Opinions, motivations, emotions
Collected via: interviews, focus groups, open questions
✓ Reveals the WHY behind behaviour ✗ Hard to analyse; time-consuming
Sampling
Sampling Methods
Businesses cannot ask every customer — they take a sample (a representative group). The method affects how reliable the results are.
Random sampling: Every person in the target market has an equal chance of being selected. Most statistically representative — but logistically difficult and expensive.
Stratified sampling: Population divided into groups (e.g. age bands), then randomly sampled from each. Ensures proportional representation of all groups.
Quota sampling: Interviewers fill pre-set quotas per group (e.g. 50 men aged 18–30) — not random, but faster and cheaper. Most widely used in practice.
Snowball / convenience sampling: Ask existing respondents to refer others. Fast but highly biased — not representative.
Critical Thinking
Reliability, Validity and Bias
Sample size: Larger samples → more reliable. A survey of 20 people in a city of 500,000 is not representative.
Leading questions: "Don't you agree our product is excellent?" — biases responses. Questions must be neutral.
Response bias: People tend to give socially acceptable answers — actual behaviour may differ (e.g. claiming to eat healthily but buying junk food).
Outdated data: Secondary data from 3 years ago may not reflect current trends — especially post-pandemic or in fast-moving tech markets.
Cost vs accuracy trade-off: Perfect research is unaffordable. Businesses balance research cost against decision importance.
Application
How Research Feeds Into the Marketing Mix
Product: Identifies gaps in the market or features customers want
Price: Determines what customers will pay; compares competitor pricing
Promotion: Reveals which channels the target market uses (social media, TV, etc.)
Place: Shows where customers prefer to shop — online, local store, supermarket
Exam tip: When evaluating market research in a case study, always consider: How large was the sample? Is the data primary or secondary? How recent is it? Could it be biased?
Practice Question 1 of 3
A clothing brand holds a focus group with 12 teenagers to discuss their opinions on a new jacket design. This is an example of:
ASecondary quantitative research
BPrimary qualitative research
CPrimary quantitative research
DSecondary qualitative research
Correct: B. A focus group is primary (collected first-hand by the business) and qualitative (generates opinions and feelings, not numerical data). The business is finding out WHY teenagers like or dislike the design — that's qualitative insight.
Practice Question 2 of 3
Which of the following is a disadvantage of secondary market research?
AIt is expensive and slow to collect
BIt can only collect numerical data
CThe data may be out of date or not specific to the business's needs
DIt requires a large team of researchers
Correct: C. Secondary research uses existing data collected for a different purpose, so it may be out of date or not tailored to the business's specific question. Option A describes primary research. Secondary research is actually cheap and fast — that's its main advantage.
Practice Question 3 of 3
A supermarket wants to survey its customers. It sets a target of interviewing 100 customers aged 18–30, 100 aged 31–50 and 100 aged 51+. This is an example of:
ARandom sampling
BSnowball sampling
CConvenience sampling
DQuota sampling
Correct: D.Quota sampling involves dividing the population into groups and setting a target number to interview from each group. It is not random — interviewers choose who to approach — but it ensures each age group is represented. It's widely used because it's faster and cheaper than stratified random sampling.
Summary
Key Distinctions to Remember
Primary vs Secondary
Primary: New data collected by the business — costly but specific and current.
Secondary: Existing data — cheap and fast but may be outdated or non-specific.
Quantitative vs Qualitative
Quantitative: Numbers — easy to analyse, shows WHAT is happening.
Qualitative: Opinions — reveals WHY, harder to analyse.
Golden exam rule on market research
Always evaluate: sample size, recency, bias, cost and purpose. Research is only valuable if it leads to better decisions — always link findings back to the business context.