Question

help please

Answer 1

A polling firm would like to predict the results of the upcoming provincial election. For each of the following proposed sampling schemes identify (i) the type of sample that is obtained and (ii) any bias in the way the sample is chosen.

Answer 2

The polling firm obtains a list of all eligible voters in the province and randomly chooses 300 of them to contacted by telephone.

Answer 3

its a random sample but its not necessarily a representative sample

Answer 4

The polling firm buys advertising space on several popular websites asking visitors to the site to respond to a short survey.

Answer 5

what about that one

Answer 6

I though that one is convenience sample

Answer 7

yeah i think, is that the one where its self-selected

Answer 8

The polling firm randomly selects 50 voters from each of the provinces electoral ridings and contacts them by telephone.

Answer 9

is it stratified sampling?

Answer 10

this one is representative...i think so, sorry i forgot the exact terms

Answer 11

any bias?

Answer 12

no not if each set of 50 is selected randomly

Answer 13

Employees of the polling firm go to busy shopping centres in cities and towns across the province and survey individuals who are shopping there.

Answer 14

what about that one

Answer 15

its the convenience one again

Answer 16

there will be bias right?

Answer 17

last one ,
The polling firm selects a random sample of five electoral ridings in the province. In each selected riding, they then select a random sample of ten streets. An employee then goes door-to-door to survey all eligible voters who live on those streets.

Answer 18

I think that one is multistage sample

Answer 19

yes there is a bias

not sure on this one... havn't heard of multi-stage

Answer 20

ok , thank you very much