non reprsentative sampling methods

Question 1

what is snowball sampling?

Answer 1

when u have 1 or 2 contacts who can take part then you intorduce to others
- so sample grows

Question 2

adv and dis of snowball?

Answer 2

adv:
-reach other grps easily e.g crimanals
dis:
-not very reprsentative, more likely from a specfic area and baised

Question 3

what is volunteer sampling?

Answer 3

advertise so respondents come forward

Question 4

adv and dis of volunteer?

Answer 4

adv:
-useful to gain access to certain individuals
dis:
-may not be very representative, low response rate and paricular grp likely to respond

Question 5

whats opportunity sampling?

Answer 5

ask certain individuals e.g homeless go toa homeless shelter

Question 6

adv and dis of opportunity

Answer 6

adv:
-guarenteed to find specfic indivualds
dis:
- respondents only from one place. not very reprsentative