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parameter statistic bias random sample survey experiment observational study Vocabulary

Concept

Classify Study Types A. Determine whether the situation describes a survey, an experiment, or an observational study. Then identify the sample, and suggest a population from which it may have been selected. MOVIES A retro movie theater wants to determine what genre of movies to play during the next year. They plan to poll 50 random area residents and ask them what their favorite movies are. Answer: This is a survey, because the data are collected from participants' responses to the poll. The sample is the 50 people area residents that are polled, and the population is all area residents. Example 1A

Classify Study Types B. Determine whether the situation describes a survey, an experiment, or an observational study. Then identify the sample, and suggest a population from which it may have been selected. DRIVING A driving school wants to determine the main issue drivers face while taking the driving test. They watch and record 30 random people taking the test. Answer: This is an observational study, because the school is going to observe the drivers without their being affected by the study. The sample is the 30 drivers selected, and the population is all drivers that may take the test. Example 1B

A restaurant manager provides a new entrée to 30 randomly selected tasters and observes their reactions. Determine whether the situation describes a survey, an experiment, or an observational study. A. survey B. experiment C. observational study Example 1A

Choose a Study Type A. Determine whether the situation calls for a survey, an experiment, or an observational study. Explain your reasoning. VIDEO GAMES A gaming company plans to test whether a new controller is preferable to the old one. A group of teens will be observed while using the controllers, to see which one they use the most. Answer: The teens will be observed without being affected by the study, so this is an observational study. Example 2A

Choose a Study Type A. Determine whether the situation calls for a survey, an experiment, or an observational study. Explain your reasoning. RESTAURANTS A restaurant wants to conduct an online study in which they will ask customers whether they were satisfied with their dining experience. Answer: This situation calls for a survey because members of the sample population are asked for their opinion. Example 2B

A research firm wants to test the effects of a new health drink A research firm wants to test the effects of a new health drink. Determine whether the situation calls for a survey, an experiment, or an observational study. Explain your reasoning. A. survey B. observational study C. experiment Example 2A

A. What is your favorite type of music? Identify Bias in Survey Questions Determine whether the survey question is biased or unbiased. If biased, explain your reasoning. A. What is your favorite type of music? Answer: This question is unbiased because it is clearly stated and does not encourage a certain response. Example 3

Identify Bias in Survey Questions Determine whether the survey question is biased or unbiased. If biased, explain your reasoning. B. Do you think that poisons, such as pesticides, should be sprayed on crops? Answer: This question is biased because the term "poison" could cause a strong reaction from the respondent. Example 3

B. Biased; the question is confusing. Determine whether the survey question is biased or unbiased. If biased, explain your reasoning. Are you planning on watching the ultimate sporting event, the Super Bowl? A. unbiased B. Biased; the question is confusing. C. Biased; the question addresses more than one issue. D. Biased; the question encourages a certain response. Example 3

Design a Survey COLLEGE A community college wants to determine whether college-bound students from local high schools would be interesting in taking a class at the college. State the objective of the survey, suggest a population, and write two unbiased survey questions. Answer: objective: to determine whether students that are planning on going to college would be interested in taking a class at the community college; population: all local high school students; sample survey questions: Are you planning on attending college after high school? Would you be interested in taking a course at the community college during high school? Example 4A

EMPLOYERS A company manager wants to determine whether her employees would like to add a recreation center to the workplace. Write two unbiased survey questions. A. Would it be beneficial? Wouldn’t employees be less productive? B. Would it be beneficial? How often would you use it? C. Would it be beneficial? Wouldn’t employees be happier? D. How often would you use it? Wouldn’t it interfere with work? A B Example 4A

Identify Flaws in Experiments Identify any flaws in the design of the experiment, and describe how they could be corrected. Experiment: A research company wants to conduct a study to determine whether a new fishing reel is more effective than the old reel. The experimental procedure consists of using the new reel to catch fish in one lake, and using the old reel to catch fish in another nearby lake that is randomly chosen. Results: The company concludes that the new reel is twice as effective as the old reel. Example 5

Identify Flaws in Experiments Answer: The flaw is that the fishing reels were used in two different lakes. The amount or type of fish in the two lakes may not be similar enough to perform a controlled experiment. Example 5

Experiment A researcher wants to conduct a study to determine the effectiveness of new golf ball. They get 50 players with different playing abilities and compare their scores. They conclude that the new ball is more effective. A. There are no flaws in this experiment. B. They need to compare the scores of a group using the new ball with the scores of the same group using a different ball. C. They need to compare the scores of players with the same ability. D. They need to compare the scores of a group using the new ball with the scores of a different group using the same ball. Example 5

Design an Experiment PETS A research company wants to test a new food for overweight cats that promotes weight loss. State the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure. Example 6

Design an Experiment Answer: objective: to determine whether overweight cats given a new weight loss food will lose weight; population: all overweight cats; experimental group: a group of overweight cats given the food; control group: a group of overweight cats given their regular food; sample procedure: The two groups of cats could be weighed at the start of the experiment and then the experimental group could be given the new food and the control group could be given their regular food. Then, after a certain period of time, the two groups could be weighed again, and the weights of the cats could be compared to determine any effect. Example 6

DE-ICERS A research company wants to test a new de-icer for frozen locks. Determine the experimental and control groups, and describe a sample procedure. A. experimental: a group where the new de-icer is used; control: a group where a different de-icer is used. The performances of the new de-icer and the control de-icer are then compared B. experimental: a group where a different de-icer is used; control: a group where the new de-icer is used. The performances of the new de-icer and the control de-icer are then compared. C. experimental: a group where the new de-icer is used; control: a group where a different de-icer is used. D. experimental: a group where a different de-icer is used; control: a group where the new de-icer is used. Example 6

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