sampling

Question 1

what determines how good a sample is?

Answer 1

the better a sample is, the more it looks like the original population.

Question 2

what do we call a good sample?

Answer 2

A REPRESENTATIVE sample

Question 3

what is sampling?

Answer 3

The process by which researchers pick a sample from the population, is known as sampling.

Question 4

what are the 5 types of sampling?

Answer 4

1. Volunteer sampling
2. opportunity sampling
3. systematic sampling
4. random sampling
5. stratified sampling

Question 5

what is volunteer sampling?

Answer 5

when an advert is posted, and people volunteer to be participants in a study.

Question 6

what are the advantages and dissadvantages of volunteer sampling?

Answer 6

pro: easy, not time consuming, and can reach alot of people.
CON: people who volunter are not so likly to be representative to the general population, beacuse not everyone is so outgoing.

Question 7

what is oportunity sampling?

Answer 7

When the researcher approaches participants,who are willing, and available at the time.

Question 8

What are the advantages and dissadvantages of opprtunity sampling?

Answer 8

PRO: quick, and easy to take participants.
CON: The sample wont be very representative to the population.

Question 9

compare volunteer sampling to opportunity sampling.

Answer 9

1. They are both easy In volunteer sampling all you have to do is put up an add, and wait, and in opportunity sampling, all you have to do is go talk to people.

They are both easy, howver it is a bit harder to go talk to people, therefore, volunteer sampling is a bit easie than opportunity sampling.

2. Opportunity sampling is a bit more representative than volunteer sampling, because the researcher actually selects the people.

Question 10

what is systematic sampling?

Answer 10

systematic sampling is picking every nth person from the ENTIRE population.

Question 11

what are the pros and cons of systemati sampling?

Answer 11

PROS: It will often lead to a more representative sample when compared to opportunity and volunteer sampling.
CONS: Difficult to do, because it requires a list of the entire population, which can be hard to obtain, if the population si large in size.

Not always representative ( patter could be wrong by simple coincidence)
-so if there is a pattern, sample might not be representative.

Question 12

What is random sampling?

Answer 12

picking randomly from a list of the ENTIRE population, so that EVERYONE HAS AN EQUAL CHANCE of being a participant.

Question 13

what are the pros of random sampling?

Answer 13

More likely to be representative to the population, because everyone has an equal chance o being picked.

Question 14

What are the cons of random sampling?

Answer 14

1. Can be difficult to pick randomly of a list, if there are alot of people in a poulation
2. Randomisation might not generate a representative sample ( by coincidence).

Question 15

What is stratified sampling?

Answer 15

When researchers sample has the same proportion of each subgroup in a population, as the population itself.

Question 16

describe all the steps of stratified sampling.

Answer 16

1. Identify the relevant sugroups in a population.
   -Need to know what the population looks like.
2. Identify how many people from each subgroup are needed to have the same proportion as the original population.
3. randomly sample from each subgroup, to get that number.

Question 17

What are the pros of stratified sampling?

Answer 17

Best way to ensure that sample resembles the poplation, therefore it is alot more representative, this means that the results of the experiment are more likely to generalise to the entire population,thus, increasing the population validity.

Question 18

what are the cons of stratified sampling?

Answer 18

1. Researchers may miss out on important subgroups, which means the sample may not be completely representableto the population
2. It is diffuclt and time consuming, since it can be hard to identify the subgroups, and also find the exact ammount of participants needed from each subgroup.

Question 19

Check graph on page 48 for clarification.

Answer 19

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