Data collection Flashcards
1
Q
Census
A
measures every member of a population
2
Q
Notes on census
A
- accurate result
- time consuming
- expensive
- hard to process large quantity
data - testing may destroy item
3
Q
Notes on sample
A
- less time consuming
- less expensive
- not as accurate
- not large enough to give info
- less data to process
4
Q
Sample
A
- selection of observations
- from subset of population
- gives info about whole population
5
Q
Sampling units
A
individual units of population
6
Q
Sampling frame
A
- individually named/ numbered sampling units
- in a list
7
Q
Simple random sampling
A
every sample size n has equal chance of being selected
7
Q
Systematic sampling
A
- elements chosen at regular intervals from ordered list
- every kth unit
- k = population/sample
7
Q
Stratified sampling
A
- popn divided into mutally exclusive strata
- random sample taken from each
- (number in stratum/ number in population) x overall sample size
- use random picking
7
Q
Notes on simple random
A
- no bias
- easy and cheap for small popn
- need sampling frame
- large and expensive for big popn
7
Q
Notes on systematic sampling
A
- simple and quick
- good for large samples
- sampling frame needed
- can be biased
8
Q
Notes on stratified sampling
A
- long and expensive
- sampling frame needed
- accurately reflects
9
Q
Quota
A
interviewer selects sample that reflects characteristics of whole population
10
Q
Quota notes
A
- bias
- quick and easy
- small sample is representative
- comparison between groups
- no sampling frame
11
Q
Opportunity sampling
A
sample from people available at the time
