Session 9: Quantitative data collection

Question 1

Describe the concepts ‘population’, ‘sample’, and ‘sampling frame’.

Answer 1

population = all units you wish to study

sample = the segment of population that is selected for investigation

sampling frame= essentially a list or database of all the elements in a population from which a sample can be drawn

Question 2

What is meant by generalization (also known as external validity)?

Answer 2

Generalization, also known asexternal validity, refers to the extent to which the findings from a study or sample can beapplied to the broader population or to other settings, groups, or timesbeyond the specific conditions of the research.

In other words, it’s abouthow well the results “travel”—can you take the conclusions from your study and confidently say they hold true for others outside of your sample?

Question 3

What is meany by representative sample?

Answer 3

Arepresentative sampleis a subset of a population thataccurately reflects the characteristics(such as age, gender, income, education level, etc.) of the entire population.

In other words, the sample isa miniature version of the population, so that conclusions drawn from it can begeneralizedreliably to the whole group.

Question 4

What is meant by probability sample?

Answer 4

Probability samplingis a sampling method where all members of the population have a known (larger than zero) or equal chance of being selected.This approach relies onrandom selection, which helps ensure that the sample is representative of the population, allowing for generalization of results and calculation of sampling error.

Question 5

What are the main types of probability sample?

Answer 5

• Simple random sample: A sampling method where every member of the population has an equal and independent chance of being selected.
• Systematic sample: A sample chosen by selecting everykth member from a list of the population after a random starting point.
• Stratified random sample: A sample drawn by dividing the population into subgroups (strata) based on shared characteristics and randomly sampling from each group.

Question 6

What are factors affecting sample size?

Answer 6

Time and cost
Heterogenity of the population (higher heterogeneity requires larger sample)
Kind of analysis to be carried out (some require large samples)

Question 7

sampling error

Answer 7

difference between sample and population