Unit 1 Analysis Of Data Flashcards
Advantages of quota sampling
Cheaper and easier
Disadvantages of quota sampling
Not genuinely random and could be biased depending on how the researcher picks
Advantages of Random sampling
Genuinely random
Free from bias
Disadvantages of random sampling
Time consuming
Costly
Needs a sampling frame
Advantages of Stratified Sampling
More accurate than random sampling
Can show different tendencies for each group
Disadvantages of Stratified sampling
Time consuming
Costly
Needs a sampling frame
Detailed planning needed
Cluster sampling advantages
Cheaper to run
Doesn’t need a sampling frame
Disadvantages of clusters sampling
Not genuinely random
Could be biased depending on clusters used
What is random sampling
Every item in the population has an equal chance of being
chosen. You assign a number to each item and then generate
random numbers in order to choose a sample (ignoring any
repeated numbers).
What is stratified sampling?
The population is divided into categories (strata) by age, gender , social class etc. Then a random sample is generated
from each group. The size of each sample is in population to the size of each category in the sample (i.e. if half the
population are children, half the sample must be children).
What is cluster sampling
The population is divided into groups (clusters). A random
sample of clusters is chosen and every item in the chosen
cluster is surveyed. The smaller the size of each cluster, the
less likely the sample is biased.
What is Quota sampling
Specific instructions are given about the how many (quota) of
each group within the population must be included in the
sample. The actual items chosen are left to the discretion of the surveyor
Equation for lower Quartile
N+1
——-
4
Upper quartile equation
3(n+1)
———-
4
