week two

Question 1

Population

Answer 1

Entire set of persons, objectives or events under study

Question 2

Source Sample

Answer 2

Subset of the population of interest

Question 3

Sampling

Answer 3

Selection of the sample

Question 4

What are the two types of sampling

Answer 4

1. Probability/Random Sampling

2. Non Probability/Non Random Sampling

Question 5

What is Random Sampling and what types of sampling does it involve

Answer 5

Random Sampling are those in which the probability of a research participant being selected is known in advance
- Important in Quantitative research

Involves:

• simple random sampling
• systematic random sampling
• stratified random sampling
• clustered random sampling

Question 6

What is non random sampling and what types of sampling does it involve

Answer 6

Likelihood of a potential research participant being selected is not known in advance
- Important in Qualitative research

Involves:

• convenience sampling
• quota sampling
• purposive sampling
• snowball sampling

Question 7

Simple Random Sampling

Answer 7

Each unit in the population has an equal and independent chance of being selected into the sample
Members of the population are selected ONE at a time, independent of one another and without replacement
E.g. Pulling a name out of a hat

Question 8

Systematic Random Sampling

Answer 8

Involves
1. Dividing the sampling frame into a number of intervals
2. Randomly selecting a starting point
3. Selecting one element from each interval in a systematic way
Don’t use if there’s a possibility of bias in the arrangement
E.g. lining up participants and choosing every tenth person

Question 9

Stratified Random Sampling

Answer 9

Divide the sampling population into separate, non-overlapping groups (strata), then randomly select from within each stratum

Two types: 
Proportionate sampling (20%-20%)
Disproportionate sampling (20%-30%)

Question 10

Clustered Random Sampling

Answer 10

Certain number of clusters are randomly sampled using simple, systematic or stratified random sampling
Sampling unit is the cluster rather than the individual
Better to sample a large number of clusters and smaller random numbers within those clusters

Question 11

Convenience sampling

Answer 11

Getting the number of people you want in a convenient manner without considering the degree to which the sample is representative

For example, choosing random students on campus (choosing from Thursday students, may be more health students compared to business)

Question 12

Quota Sampling

Answer 12

Selection of individuals with certain visible characteristics (gender, ethnicity) using a matrix

Question 13

Purposive Sampling

Answer 13

Sampling only individuals who can provide the desired information
– Population of interest is small
– Selection of information-rich cases for study in depth

Question 14

Snowball Sampling

Answer 14

Uses network to identify the sampling. Going from one person to another, population becoming bigger

For example asking someone to suggest two other people who could contribute to this research, then asking those two people the same question. Social media is useful in this(people retweeting, liking pages etc)