Populations, sampling and sampling techniques Flashcards
WHAT IS OPPORTUNITY SAMPLING?
Sample of people who are available at the time.
STRENGTHS OF OPPORTUNITY?
Quick and convenient to obtain. Often ps are very willing to participate.
WEAKNESSES OF OPPORTUNITY?
Biased, ps may want to please the investigator who may be known to them.
WHAT IS RANDOM SAMPLING?
Equal chance of been chosen.
STRENGTH OF RANDOM?
Not biased, representative reflection of the target population: the group of people from whom the sample is drawn.
WEAKNESS OF RANDOM?
Practically difficult to obtain a truly random sample.
WHAT IS SNOWBALL SAMPLING?
Start with a small group and contact more ps through that initial sample.
STRENGTHS OF SNOWBALL?
Easy and convenient to find a sample.
WEAKNESSES OF SNOWBALL?
Lazy and biased- not representative.
WHAT IS VOLUNTEER SAMPLING?
Ps volunteer, they respond to an ad.
STRENGTHS OF VOLUNTEER?
Given consent and convenient.
WEAKNESSES OF VOLUNTEER?
Depending on where you display the advert, demand characteristics could be displayed as ps could be cooperative.
