Data Collection

Question 1

Advanatges of a census

Answer 1

It should give a completely accurate result

Question 2

Advantages of a sample

Answer 2

• Less time consuming
• Less expensive
• Fewer people have to respond
• Less data to process

Question 3

Diasdvanatges of a census

Answer 3

• Time consuming and expensive
• Cannot be used for destructive testing
• Hard to process large quantities of data

Question 4

Disadvanatges of a sample

Answer 4

• The data may not be as accurate
• The sample may not be big enough to give data about small sub groups.

Question 5

What is a population?

Answer 5

A whoile set of items that are of interest

Question 6

What is a sample?

Answer 6

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

Question 7

What is a census?

Answer 7

Observes or measures every member of a population

Question 9

What is stratified sampling?

Answer 9

The population is divided into mutually exclusive strata and a random sample is taken from each
The proportion from each strata should be the same

Question 9

Advantages of random sampling

Answer 9

• It removed bias from the sample
• It should be representative of the population

Question 9

What is a sampling unit?

Answer 9

An induvidual unit of a population

Question 9

Advantages of simple random sampling

Answer 9

• Free of bias
• Easy and cheap to implement for small populations
• Each sampling unit has a known and equal chance of being selected

Question 9

What is simple random sampling?

Answer 9

Every sample has an equal chance of being selected.
You need a sampling frame where each person or thing is assigned a unique number, a selection of these numbers is then chosen at random
Numbers are either randomly generated or drawn through the lottery method.

Question 10

Disadvantages of simple random sampling

Answer 10

• Not sutable when the population size is very large
• A sampling frame is needed

Question 11

Advantages of systematic sampling

Answer 11

• Simple and quick to use
• Sutable for large samples and large populations

Question 12

Advantages of stratified sampling

Answer 12

• Sample accurately reflects the population structure
• Guarantees proportional representation

Question 13

Disadvantages of systematic sampling

Answer 13

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

Question 14

Disadvantages of stratified sampling

Answer 14

• Population must be clearly clasified into distinct strata
• Selection within each stratum suffers from the same disadvantages as simple random sampling

Question 15

Advantages of quota samping

Answer 15

• Allows a small sample to still be representative
• No sampling fram required
• Quick, easy and inexpensive
• Allows for easy comaprision between different groups within a population

Question 16

Disadvantages of quota sampling

Answer 16

• Non random samping can introduce bias
• population must be divided into groups
• Increasing score increases the number of groups incresing time and expendse
• Non responses are not recorded as such

Question 17

What is quota sampling?

Answer 17

An interviewer or resercher selects a sample that reflects the characteristics of the whole population

Question 18

What is opportunity sampling?

Answer 18

A sample is taken from people who are availabe at the time the study is carried out and who fit the criteria you are looking for

Question 19

Advantages of opportuinty sampling

Answer 19

• Easy to carry out
• Inexpensive

Question 20

Disadvantages of opportunity sampling

Answer 20

• Unlikely to provide a representative sample
• Highly dependant on induvidual reasercher