Scientific investigation

Question 1

Define the term accuracy

Answer 1

• the closeness of a measured value to a standard or known value

Question 2

Define the term precision

Answer 2

• the closeness of two or more measurements to each other

Question 3

Define the term representative sample

Answer 3

• a sample that represents the whole population

Question 4

Define hypothesis

Answer 4

• a statement that you test through research and experiments

Question 5

Define null hypothesis

Answer 5

• type of statistical hypothesis that proposes that no significance exists in a set of given observations

Question 6

Define random sampling

Answer 6

• type of probability sampling in which the researcher randomly selects a subset of participants from a population

Question 7

Define systematic sampling

Answer 7

• a probability sampling method where researchers select members of the population at regular intervals

Question 8

Define stratified sampling

Answer 8

• involves the division of a population into smaller subgroups

Question 9

What should you consider when deciding the number of samples in a study

Answer 9

• size of population
  -variability in population

Question 10

What is a standardised sampling method and why is it important

Answer 10

• method that allows data to be collected in exactly the same way by different people at different times
• give clear methods and equipment
• control any variables

Question 11

Why is timing important in experimental design

Answer 11

• time of day, night
• if organisms have a life cycle e.g hibernation
• migration patterns

Question 12

What is a belt transect

Answer 12

• sample along a route at regular intervals

Question 13

What is an abundance scale and why are they useful

Answer 13

• way of applying what you see to a category
• doesn’t require counting

Question 14

What are the limitations of an abundance scale

Answer 14

• subjective
• no statistical tests
• relies on human observations ( room for error )

Question 15

What are the 3 types of quadrats

Answer 15

• open frame
• grid
  -point

Question 16

What is kick sampling and what are the limitations

Answer 16

• hold a net downstream and disturb the bed of water and collect sediment in net
• different efforts put into kicks
  -some organisms can swim

Question 17

What is suber sampling and what are the limitations

Answer 17

• same as kick sampling but with a frame on where you kick
• ground could be uneven

Question 18

What is colonisation media and what are the limitations

Answer 18

• provide a habitat for the organism that you’re counting
• organism isn’t attracted to it
• don’t have total population size

Question 19

What is a pitfall trap and what are the limitations

Answer 19

• dig a hole and place a cup in the ground and insects will fall into it
• some could escape
• organisms could eat one another

Question 20

What is a sweep net and what are the limitations

Answer 20

• sweep a net in a figure of 8 to catch things such as moths in a large field
• organism could be harmed
• organism could escape

Question 21

What is a beating tray and what are the limitations

Answer 21

• beat a huge net underneath a tree and invertebrates will fall and land on the tray
• organisms can fly
• organisms could remain in the tree

Question 22

What is a light trap and what are the limitations

Answer 22

• using uv, white light to catch moths
• could escape before counting
• different species of moth are attracted to different wavelengths of light

Question 23

What is a tullgren funnel and what are the limitations

Answer 23

• collect a soil sample, and it filters down the tunnel and organisms are caught in a dish at the bottom
• heat may harm the organisms
• some organisms may be too big to filter all the way down

Question 24

What is earthworm extraction and what are the limitations

Answer 24

• add an irritant, water or stamp on the ground to attract the worms upwards
• irritant could kill the worms
  -worms could move sideways instead of upwards

Question 25

What are examples of indirect monitoring methods

Answer 25

• camera trapping
  -drones
• satellites
• thermal cameras

Question 26

What are some quantitative measures

Answer 26

• abundance scale - DAFOR
• population size
• species diversity
• species density