LECTURE NOTES - SAMPLING
SAMPLING Sampling - accurate way of representing whole population without asking everybody.
asking everyone = cost time & money (even w/ best/most expensive effort)
SAMPLING IN know population & list so that you need to ask everyone.
GENERAL # of ppl to be sampled = depends on range of opinions &behaviours & size of population.
cheaper, faster and almost as accurate (w/ greater knowledge of where/how results inaccurate)
BIASES IN SAMPLING BIAS
SAMPLING bias sampling = cases/ppl= not typical /representiative of population
some elements of population = more / less likely sampled.
Eg: adv of knowing where or how samples are = may be biased or insufficient
representing one or more pop &sub group
RANDOM PROBABILITY (RANDOM) SAMPLING
use population parameters to estimate the probably margin of error.
SAMPLING utilizes some form of random selection
through process / procedure that assures everyone in population has equal
probabilities of being chosen.
NON-RANDOM NON-RANDOM SAMPLING
SAMPLING surveying through accessibility or availability of circumstances or people.
3. representative sample
1. convenience sampling (ca few questions then couquota sampling = Need to surveyst likely & extremes)t /
who you could grab randomlrecommend someone to) certain amount of ppl. (representative or informants)