Sampling

Question 1

What’s opportunity sampling ?

Answer 1

Parts are chosen because they’re available

Eg; uni students selected because they’re around at that time

Question 2

Strength And Weakness of opportunity sampling

Answer 2

+Quicker and easier as parts are readily available

-Non representative, people available are likely to be limited and similar making the sample biased

Question 3

What’s self self selected sampling ?

Answer 3

Parts are invited to participate (Volunteer)

Eg through adverts

Question 4

Strength And Weakness of self selected sampling

Answer 4

+Easy because parts come to you and are committed and are likely to turn up for repeat testing
-volunteers may have similar characteristics (Atypical/unusual in some way) Eg;Sperrys study

Question 5

What’s snowball sampling

Answer 5

From a very small no of parts, More are contacted through the initial group

Question 6

Strength And Weakness of snowball sampling

Answer 6

+Easy As only need to find first few
+convenient way- sample of a particular type of parts (Eg; gangs)
-non representative as they’re likely to be similar in ways other than common characteristics needed for the study

Question 7

What’s random sampling ?

Answer 7

All members of population has an equal chance of being picked & a fixed amount is selected in an unbiased way
Eg;taking number out of a hat

Question 8

Strength And Weakness of Random sampling

Answer 8

+representative as there’s an equal chance of being chosen

-Hard to ensure everyone is equally likely to be chosen (Eg: if girls happen to be selected)-Bias

Question 9

What’s stratified sampling

Answer 9

Individuals are taken to represent each major strata or later within the population
Eg; a study conducted in a school should ensure children from each academic year is selected

Question 10

Strength And Weakness of stratified sampling

Answer 10

+Representative As all types of people in the population are represented
-Difficult As subgroups Ik population must be known and accessible