Define the concept of a bias sample.?

Question

What does it mean and can i get examples.

Answer 1

I think you mean a biased sample. Normally when trying to draw conclusions about a widespread phenomenon you can't do a census and tabulate all the instances to characterize them.

So you end up taking a representative sample of the larger population and draw conclusions about them, applying the trends to the larger population.

When doing this (as in taking a political poll, for example) you have to make very sure that you're taking a random, truly representative sample of the overall population.

If for example you did a political opinion poll and only called people that you found on the Republican party donor list, you'd be drawing from a non-random audience and you wouldn't truly get results that could be applied to the entire population.

Because a sample of this type isn't truly random, it is described as being biased and would be considered scientifically invalid.

Another example would be if you wanted to gather information about the physical fitness of teenagers in America. If you got your information from the track team at a high school, you would indeed have information from teenagers, but not from the entire spectrum of teenagers, and again your sample would be biased.

Answer 2

A biased sample is one that is falsely taken to be typical of a population from which it is drawn. Someone saying "Everyone liked that movie!" might not mention that the "everyone" was them and three of their friends, or a group of the star's fans.

eg.
u want to do a survey of how much pocket money does primary school student have.
an example of a bias sample would be to pick random students from the primary 1 students only.

Answer 3

a bias sample means to alter the reader's judgement
an example would be like saying this:
2 competitor are selling milk

the first guy's sign is this:
$1 a gallon
the second guys sign is this:
$.50 a cup

the reader thinks that the second guy is cheaper because they have a lower cost, but in reality the first guy is cheaper because the milk is measured in different units

example 2:
$5 for 4 books
vs
$4 for 3 books

you think that the second one is cheaper but it's not
if you buy 12 books, you would spend $15 on the first one, but $16 dollars on the second one

this is kinda long,srry i hope you understand it now