Question

estion 2. 17 marks] [Chapter 4] The marketing manager of a new company that manufactures teabags wants to get feedback on how consumers in New Zealand rate their product compared to existing products. He is considering several different strategies: Strategy 1: Place an advertisement in a major newspaper inviting people to visit a website to sign up for a free sample of their teabags. Those who sign up are then posted a sample with a request to fill in an on-line questionnaire about it. Strategy 2: Select a random sample of 500 people from the Electoral Roll and post them a sample of their teabags with a request to fill in an on-line questionnaire about them. The 500 people are informed that everyone who completes the on-line questionnaire will get a voucher to get a free box of the company's teabags. Strategy 3: Set up booths at several shopping malls in large cities in New Zealand. Every 10th person who passes is asked by an interviewer to try their teabags and then fill in a paper questionnaire ) For which strategy is self-selection bias a potential problem? ) For EACH of the strategies, explain how selection bias may be a potential problem. 13 Marks] ) What form of bias is the voucher offer in Strategy 2 trying to minimise? This is probably not a ) Which strategies, if any, are subject to sampling error? Il Mark) sensible strategy - briefly explain why. [2 Marks] [1 Mark]

Answer 1

Answer1.

1.For which strategy selection bias a potential problem

Selection bias- Self-selection bias is a bias which is  introduced into a research project when participants to the survey choose whether or not to participate in the survey, and the group that chooses to participate is not equivalent to the group that opts out.

In the above 3 strategies strategy 2 i.e (election of random sample of 500 people) has a self selection bais potential problem because results would be severely affected by self selection bias because only those who received the sample of tea bag will do questionnaires and  likely to send it back.

Answer 2.

For each strategy explain how selection bais a potential problem.

strategy1.

Advertisement is placed in newspaper,to visit website ,sign up ,get free sample of teabag ,and fill questionnaires.First of all the survey will ignore group of people who do not read newspapers, so here many group of participants are avoided to arrive at correct result.so here self selection bias will become problem.

Strategy2.In this strategy selection of random sample of 500 people from electoral roll,results would be severely affected by self selection bias because only those who received the sample of tea bag will do questionnaires and  likely to send it back ,due less involvement of participants,survey will be biased.

Strategy 3. setting booth at several shopping mall,surveying the every 10th people and asked to fill questionnaire. This startegy is better than other startegy, it will have less self selection bias problem but it should not be a single day task,it should go for long time say 1 month to analysis result otherwise it will be baised.

Answer 3.

In strategy 2 the new company is trying to minimise comformation bias,and error in filling incorrect details about questionnaire .A voucher will be provided who will successfully fill up the questionaire ,the people who are selected which are 500 in numbers ,must give filled questionnaire .The whole 500 people selected will confirm the survey.

This is not a sensible strategy, because teabag market is large enouqh ,there are people with different taste ,preferences. Surveying on small number of people is not good strategy.

Answer 4.

Strategy 2 will give sampling error, because only those who received the sample of tea bag will do questionnaires and  likely to send it back.

And surveying on small number of people is not good strategy.