Chapter 1

Question 1

What is a population?

Answer 1

It is the whole set of items of interest

Question 2

Census

Answer 2

Observes or measures every member of a population

Question 3

Sample

Answer 3

Selection of observations taken from a subset of the population, which is used to find out information about the population as a whole

Question 4

Sampling units

Answer 4

Individual units of a population

Question 5

Sampling units *

Answer 5

Individual units of a population

Question 6

Sampling frame

Answer 6

Sampling units are individually named or numbered

Question 7

Census advantage and disadvanatge

Answer 7

Accurate result

Time consuming
Expensive
Can’t be used if product is destroyed
Harder to process data

Question 8

sample advantage and disadvantage

Answer 8

Cheaper and quicker than census
Less people required to respond
Less data to process

Data is less accurate
Sample may not be large enough to give information about small subgroups

Question 9

Simple random sample method

Answer 9

• Allocate a number to each member
• Use a calculator or random num generator to generate random numbers for the number of people you want to sample
• Select the people corresponding to these numbers

Question 10

Simple random advantage and disadvantage

Answer 10

Free of bias
Easy and cheap for small populations
Each sampling unit has a known and equal chance

Not suitable when sampling size is large
A sampling frame is needed

Question 11

Systematic sampling method

Answer 11

• Choose the required number of people at regular intervals.
• Pick the starting point between 1 and the size of intervals

Question 12

Systematic advantage and disadvantage

Answer 12

Simple and quick
Suitable for large samples

A sampling frame is required
It can introduce bias if the sampling frame is not random

Question 13

Quota sampling method

Answer 13

• Divide the population into groups according to given characteristics
• The size of the group determines the proportion of the sample that should have that characteristic
• Once the sample size has been met, sample each member of the group- non randomly

Question 14

Quota sampling advantage and disadvantage

Answer 14

Allows a small sample to be representative of a population
No sample frame required
Quick easy and cheap
Allows for easy comparisons within different groups of a population

Can introduce bias
Populations must be divided into groups which can be costly or inaccurate
No responses aren’t recorded as such

Question 15

Opportunity sampling/ Convenience sampling

Answer 15

• Take a sample of the people who are avaliable at the time and meet the criteria you need

Question 16

Opportunity/ Convenience sampling advantage and disadvantge

Answer 16

Easy to carry out
Cheap

Unlikely to provide a representative sample
Dependent on the induvidual researcher

Question 17

Types of random sampling

Answer 17

Simple random
Systematic
Stratified

Question 18

Types of non-random sampling

Answer 18

Quota and Oppurtunity