Research Methods

Question 1

What is a hypothesis?

Answer 1

An educated guess as to what will happen during an experiment

Question 2

What is a null hypothesis?

Answer 2

A hypothesis that states there will be no change during an experiment (no statistical relationship)

Question 3

What is random sampling?

Answer 3

A subsample is chosen randomly from a larger set (e.g. random number generator)

Question 4

What is the importance of random sampling?

Answer 4

Avoids bias

Question 5

What is systematic sampling?

Answer 5

A subsample is chosen from a larger set with a fixed periodic interval (e.g access points along a river)

Question 6

What is the importance of systematic sampling?

Answer 6

Regular sample intervals

Question 7

What are the 2 types of transect?

Answer 7

• Line transect
• Belt transect

Question 8

Where are transects applied?

Answer 8

To environmental gradients

Question 9

Why is sample timing important?

Answer 9

To ensure variability is detected

Question 10

What is sample size dependent on?

Answer 10

Homogeneity

Question 11

What is sample number dependent on?

Answer 11

Variability

Question 12

Why is standardisation important?

Answer 12

To allow comparisons between different experiments and ensure consistent reliability

Question 13

What are the 3 types of quadrat?

Answer 13

• Frame
• Grid
• Point

Question 14

What do the 3 types of quadrat measure?

Answer 14

• Frame - percentage frequency
• Grid - percentage cover
• Point - local frequency

Question 15

What are the limitations of quadrats?

Answer 15

• Subjective observations
• Plants may be flattened

Question 16

What are kick sampling and surber sampling used for?

Answer 16

Sampling of freshwater invertebrate species

Question 17

How does kick sampling work?

Answer 17

1. Net held downstream in a river
2. Agitation through kicking
3. Invertebrates are caught in the net

Question 18

What are the limitations of kick sampling?

Answer 18

• Organisms may swim away
• Difficult to standardise

Question 19

How does surber sampling work?

Answer 19

1. Net attached to a frame is held downstream in a river
2. Agitation in the frame using a trowel or a stick
3. Invertebrates are caught in the net

Question 20

What are the limitations of surber sampling?

Answer 20

• Difficult on uneven river beds
• Water flow must be fast

Question 21

How can kick sampling and surber sampling be standardised?

Answer 21

• Same amount of kicks
• Same sized net

Question 22

What is colonisation media?

Answer 22

Providing a suitable habitat which is attractive to species that an individual wants to monitor (e.g. beetle banks)

Question 23

What are the limitations of colonisation media?

Answer 23

• Habitat may not be colonised
• Affects true population size

Question 24

What is a pitfall trap used for?

Answer 24

Sampling of small terrestrial species (e.g. insects)

Question 25

How does a pitfall trap work?

Answer 25

A small container is placed in the ground level to the surface and covered before being left for a period of time

Question 26

What are the limitations of a pitfall trap?

Answer 26

- More mobile organisms are caught - Possible predation in the trap

Question 27

How can a pitfall trap be standardised?

Answer 27

- Same sized container - Same preservation fluid - Same period of time it is left for

Question 28

What is a sweep net used for?

Answer 28

Sampling of invertebrates in ground vegetation

Question 29

How does a sweep net work?

Answer 29

A net is swept in a figure of eight configuration and repeated

Question 30

What are the limitations of a sweep net?

Answer 30

- Flying organisms may escape - Some organisms may be harmed

Question 31

How can a sweep net be standardised?

Answer 31

- Same number of sweeps - Same sweep length

Question 32

What is a beating tray used for?

Answer 32

Sampling of invertebrates in tall vegetation

Question 33

How does a beating tray work?

Answer 33

Vegetation is shaken and anything that falls out is collected in a tray

Question 34

What are the limitations of a beating tray?

Answer 34

- Difficult to standardise - Flying organisms may escape

Question 35

What is a light trap used for?

Answer 35

Sampling of night-flying insects (e.g. moths)

Question 36

How does a light trap work?

Answer 36

Flying insects are attracted to the UV light and are trapped, allowing for counting and identification the next day

Question 37

What are the limitations of a light trap?

Answer 37

- No moths will be present if it rains - Different insects are attracted to different wavelengths of light

Question 38

What is a tullgren funnel used for?

Answer 38

Sampling of mobile invertebrates in leaf litter or soil

Question 39

How does a tullgren funnel work?

Answer 39

A sample is placed on mesh beneath a light which causes organisms to move downward away from the light and through the mesh into a funnel and collection pot

Question 40

What are the limitations of a tullgren funnel?

Answer 40

- Only species repelled by heat or light will be collected - Only small organisms fit through the mesh

Question 41

What is earthworm extraction used for?

Answer 41

Sampling of earthworms in soil

Question 42

How does earthworm extraction work?

Answer 42

Irritant is added to the soil to force earthworms to the surface for counting and identification

Question 43

What are the limitations of earthworm extraction?

Answer 43

- Earthworms may move deeper - Earthworms may die

Question 44

What is the most common abundance scale?

Answer 44

DAFOR

Question 45

What does DAFOR stand for?

Answer 45

Dominant Abundant Frequent Occasional Rare

Question 46

What is species frequency?

Answer 46

A measure of the dispersal of a species by recording the proportion of samples in which they were found

Question 47

What does the Lincoln Index calculate?

Answer 47

An estimate of species' population size (capture, re-capture)

Question 48

What are the limitations of the Lincoln Index?

Answer 48

- Assumes no population change - Assumes marked individuals mix freely with the rest of the population

Question 49

What does Simpson's Index of Biodiversity calculate?

Answer 49

Biodiversity of an area