stastistical sampling

Question 1

what are the 6 sampling methods?

Answer 1

stratified
systematic
quota
random
cluster
opportunity

Question 2

what is a population

Answer 2

the entirety of what your testing

Question 3

what is a sample

Answer 3

a small section (subset) of the population

Question 4

what is a census

Answer 4

survey on the entire population

Question 5

✅ and ❌ of a census

Answer 5

✅ accurate results

❌ time consuming
expensive
test items must remain intact

Question 6

✅ and ❌ of a sample

Answer 6

✅ quicker
easier

❌ bias - unrepresentative

Question 7

why might sampling methods be unsatisfactory?

Answer 7

sample size is too small
sample is unrepresentative
biased

Question 8

what is a sampling unit

Answer 8

each individual from a sampling list

Question 9

what is a sampling frame

Answer 9

a list of sample units
named or numbered

Question 10

cluster sampling

Answer 10

when population is separated into clusters and random clusters are sampled

Question 11

✅ and ❌ of cluster sampling

Answer 11

✅ cheaper
Larger samples
Quick

❌ bias

Question 12

stratified sampling

Answer 12

population divided into groups and random samples taken from each group to fill calculated categories

Question 13

✅ and ❌ of stratified sampling

Answer 13

✅ random
representative

❌ time consuming
need a sampling frame- unit

Question 14

random sampling

Answer 14

picking at random so each member has an equal chance

Question 15

✅ and ❌ of random sampling

Answer 15

✅ no bias

❌ unrepresentative
time consuming for large population

Question 16

opportunity sampling

Answer 16

picking units that are easiest to reach

Question 17

✅ and ❌ of opportunity sampling

Answer 17

✅ easy
quick

❌ bias - unrepresentative

Question 18

quota sampling

Answer 18

population is split into groups and units selected till quotas (calculated group to represent) are filled

Question 19

✅ and ❌ of quota sampling

Answer 19

✅ representative

❌ bias

Question 20

systematic sampling

Answer 20

choosing at intervals - nth terms

Question 21

✅ and ❌ of systematic sampling

Answer 21

✅ quick
easy

❌ must have a list to avoid bias

Question 22

what is the equation to work out category sizes for stratified sampling?

Answer 22

size of sample/size of population x no of units within a group= category size