Sample methods
20/09/2022 13:41
Sample size
• What is sample size - The size of the area of the
transects/quadrants that are being surveyed
that will make up the calculation which
estimates data for the total area.
• The more total area of sample size surveyed
will result in more accurate results. For example
if you survey 5/100 quadrants that will be less
accurate then surveying 30/100 quadrants.
• However bigger is not always necessarily better
as bigger areas can reduce precision and
accurate observations due to their being more
area to survey and therefore increase time
consumption.
Sampling techniques
• The two types are:
○ Random - a subset of the statistical
population of which each area/member
has an equal chance of being chosen.
○ Systematic - a subset of the statistical
population where a random starting
point is chosen but then the other
areas/members are systematically chosen
based on a chosen interval number. For
example the researcher may begin with a
random starting number of area 5
(random starting point) however decide
to sample every 10 areas (chosen interval
number) after.
Techniq Pros Cons
ue
Simple • Unlikely to • Not very accurate
Random be biased as may not cover
• Simple/ easy range of
to carry out population
• Can still be
biased in certain
circumstances
• Lack of additional
20/09/2022 13:41
Sample size
• What is sample size - The size of the area of the
transects/quadrants that are being surveyed
that will make up the calculation which
estimates data for the total area.
• The more total area of sample size surveyed
will result in more accurate results. For example
if you survey 5/100 quadrants that will be less
accurate then surveying 30/100 quadrants.
• However bigger is not always necessarily better
as bigger areas can reduce precision and
accurate observations due to their being more
area to survey and therefore increase time
consumption.
Sampling techniques
• The two types are:
○ Random - a subset of the statistical
population of which each area/member
has an equal chance of being chosen.
○ Systematic - a subset of the statistical
population where a random starting
point is chosen but then the other
areas/members are systematically chosen
based on a chosen interval number. For
example the researcher may begin with a
random starting number of area 5
(random starting point) however decide
to sample every 10 areas (chosen interval
number) after.
Techniq Pros Cons
ue
Simple • Unlikely to • Not very accurate
Random be biased as may not cover
• Simple/ easy range of
to carry out population
• Can still be
biased in certain
circumstances
• Lack of additional
