Sampling Technique Flashcards
determined by multiplying the length and width of the topo map
area of the site
formula to determine total area
TA = L x W
Slovin’s formula for sample size
n = TA / 1+Tae^2
sampling selection method that will be used
quadrat sampling
any circular, rectangular, or square plot used to count samples
quadrat
may vary depending on the type of vegetation
size of quadrat
The more diverse the site the smaller/bigger the quadrat size
bigger
formula for the number of quadrats
NQ = Sample Size / Quadrat Size
process of getting a small portion from the whole
sampling
can be organisms, activities, observations, or measurements like weights, heights, etc. that represent the population
sample
Sampling methods include the following
probability sampling
non-probability sampling
every member of the population has a chance of being selection
probability sampling
individuals are selected based on non
-random criteria, and not every individual has a chance of being included
non-probability sampling
selection is based on the principle of randomization by chance
probability sampling
More complex, more time consuming, and more costly than non-probability sampling
probability sampling
type of probability sampling (4)
simple random sampling
cluster sampling
systematic sampling
stratified random sampling
every member of the population has an equal chance of being selected
simple random sampling
divides the population into subgroups, but each subgroup should have similar characteristics to the whole sample
cluster sampling
Instead of sampling individuals from each subgroup, you randomly select entire subgroups
cluster sampling
every member is listed with a number, but instead of randomly generating numbers, individuals are chosen at random intervals
systematic sampling
appropriate when the population has mixed characteristics, and you want to ensure that every characteristic is proportionally represented in
the sample
stratified random sampling
Divide the population into subgroups (called strata) based on the relevant characteristics (e.g. gender, age range, income bracket, job role)
stratified random sampling
in order to draw conclusions about the population from the sample, it must assume the sample is representative of the population
non-probability sampling
a convenience sample simply includes the individuals who happen to be most accessible to researcher
convenience sampling
this involves the researcher using their judgment to select a sample that is most useful to the purposes of the researcher
judgmental or purposive sampling
method in which researchers choose individuals according to specific traits or qualities they decide and create quotas
so that the research samples can be useful in collecting data
quota sampling
research participants recruit
other participants for a test
or study
snowball sampling
1 ha is equasls to what mm^2
10,000
study how to compute the formula
+1
