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
quick for a small population

❌ cant be used if sampling units are not within a list
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

Question 23

Quota sampling formula?

Answer 23

Sample size × represntation amount = amount within the quota ( what you want to fill )

Question 24

what is a biased sampling technique?

Answer 24

one that may cause you to draw misleading conclusions for the population

which random sampling tries to reduce

Question 25

what is random sampling?

Answer 25

its where every member of the group has an equal chance of being selected