Question

Part 1. there is no such thing as a ‘bad sample’. a. True b. False Part 2.Each of the 20 English Premier League teams have a match day squad of 18 players. A sample of 40 players is to be chosen. Each team is asked to put the 18 players' names into a bag and randomly draw out two names. The two names from each team are then combined to make up the sample. Does this method result in a simple random sample of the 360 footballers? a. Yes, because each player has the same chance of being selected. b. Yes, because each team is equally represented. c. Yes, because there are squads of players used, not just the first choice 11. d. No, because not every group of 40 players has the same chance of being selected.

Answer 1

Part 1 :  False, there are many ways to select a sample—some good and some bad. If a sample isn't randomly selected, it will probably be biased in some way and the data may not be representative of the population.

Part 2 :No, a simple random sampling is when the sample is choosen from entire sampling frame (part of population you are sampling from) i.e. the 40 players are randomly choosen from ALL the possible 360 players.

Technically, a simple random sample is a set of n objects in a population of N objects where all possible samples are equally likely to happen.

In this case, players have been divided in strata by teams. From each team 2 players are choosen at random, this type of sampling is Stratified Sampling.