What are qouta sampling and convenience sampling in statistics?

Question

And how can this be used to conduct sampling by a company that markets a new personal computer???

Answer 1

Both are sources of bias and should probably be avoided except for specific circumstances. Quota sampling means that you randomly choose members of a population but discard those that don't meet certain criteria. For example. Say you stopped people at random off the street and asked if they vote republican or democrat. You added only the people who say they vote republican to your sample. Convenience sampling means you take people based on ease of availability. An example would be a random sample of people who walked into McDonald's for lunch that day.

Here is where you can get into trouble. Let's say you choose only people who use computers at work for your sample and ask them who makes the best computers. You would get a completely different answer than if you asked a sample of people who play computer games. Or, worse, let's say you were to ask a random sample of people who walked into your own store, who makes the best computers. They are already there and heavily biased to say you guys do.

Answer 2

use this site please! it will help you!

http://www.mis.coventry.ac.uk/~nhunt/meths/other.html

Regards,

friends4ever_18th