Sampling Methods

Question 1

What are the advantages in Systematic sampling?

Answer 1

• simple and convenient
• allows clear environmental gradient to be established can be completed quickly
• optimises representation over ecological space

Question 2

What are the disadvantages in Systematic sampling?

Answer 2

• potetional cost of collecting a representatice sample
• impossible to estimated the variance of one sample → it may not represnt the whole population.
• accuracy can be poor if a perodic or cyclic varaiation appears in the population
• personal bias of the investigators

Question 3

What are the advantages in Stratified sampling?

Answer 3

• representative of all areas
• provides greater precision
• often requires a smaller smaple, which saves money
• if measurements within strata have lower strandard deviation, startification gives smaller error in estimation

Question 4

What are the disadvantages in Stratified sampling?

Answer 4

• a prior knowledge is required of the strata
• rare habitats could be missed