Lesson 2 Flashcards
includes all members of a defined group studying for data-driven decisions
POPULATION
complete enumeration of a population or groups at a point in time
CENSUS
subset of population
SUBPOPULATION
selected representative of larger population
subpopulation
set of data collected from a population
sample
the formula used for sample size determination..
provide the full formula
SLOVIN’S FORMULA
n=N/1+Ne^2
in slovin’s formula, N stands for..
population size
in slovin’s formula, e stands for..
margin in error
it is the difference between the value from sample of population and the true value of population parameters
SAMPLING ERROR
true or false. surveys become useless when sampling error is involved
FALSE
the laws of probability make it possible for us to calculate intervals of the form
MARGIN OF ERROR
what makes the margin of error to be possible to calculate intervals
LAW OF PROBABILITY
intervals in margin of error is sometimes called
95% confidence intervals
margin of error formula
Estimate +/- margin of error
enumerate the stages in selecting a sample
- define the target population
- select a sampling frame
- determine if probability/non-probability sampling method will be chosen
- plan procedure for selecting sample units
- determine the sample size
- select actual sampling units
- conduct fieldwork
REASONS FOR SELECTING A SAMPLE: Complete enumeration are practically
impossible when the population is _
infinite
enumerate the types of sampling
probability sampling
non-probability
enumerate the types of probability sampling
simple random sampling
systematic sampling
stratified random sampling
cluster sampling
The sample is a proportion (a certain percent)
of the population and such sample is selected
from the population by means of some
systematic way
probability sampling
a feature of the selection
process rather than an assumption about the
structure of the population
Randomization
- Every member of the population (N) has an
equal chance of being selected for your sample
simple random sampling
- This is arguably the best sampling method, as
your sample is almost guaranteed to be
representative of your population
simple random sampling
- In this method all the items of the population
are numbered on separate slips of paper of
same size, shape and color
lottery method
- Random number can be generated through
scientific calculator or computers - For each press of the key get a new random
numbers - The ways of selection of sample is similar to that
of using random number table
Random Number Selection Using Calculators and
Computers
Is a method of sampling that involves the
division of a population into smaller subgroups
knowns as _.
stratified random sampling; strata
formed based on members’ shared
attributes or characteristics such as income or
educational attainment
strata
stratified sampling formula
stratified random sampling = total sample size/entire population x population of subgroups
- Widely employed because of its ease &
convenience - Frequently used method of sampling when a
complete list of the population is available
systematic sampling
Every nth individual from the population (N) is
placed in the sample (n)
Quasi Random Sampling
a way to select participants
randomly that are spread out geographically
CLUSTER SAMPLING
formula for systematic sampling
k=N/n
In systematic sampling, Kth item is picked up from the __and K is called the _
In systematic sampling Kth item is picked up from the sampling frame and K is called the sampling interval
Sample is not a proportion of the population and there is no system in selecting the sample
non-probability sampling
No system of selection but only those whom the researcher or interviewer meet by chance are included in the sample
Accidental Sampling/Convenience Sampling
a sample made up of volunteers
Compared to a random sample, these types of samples are always biased.
Voluntary Response Sampling
Respondents are chosen on the basis of their knowledge of the information desired
purposive Sampling
sample members are chosen only on the basis of the researcher’s knowledge and judgment
Judgement Sampling
enumerate the types of non-probability sampling
accidental/convenience sampling
voluntary response sampling
purposive sampling
snowball sampling
If the population is hard to access, __ can be used to recruit participants via other participants
Snowball Sampling
