Section 11.1 – Designing A Study EQ: In an experiment how can I classify the study, choose the type of study, determine bias, and identify the flaws of the study?

Vocab Parameter: A measure the describes a characteristic of a population Statistic: A measure that describes a characteristic of a sample (i.e. mean, standard deviation) Bias: An error that results in a misrepresentation of members of a population Random Sample: A sample in which every member of the population has an equal chance of being selected

Study Types

Example 1: Classify the Study 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. A. 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. Survey

Example 1 Cont. Observational Study Experiment B. 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. C. A restaurant manager provides a new entrée to 30 randomly selected taster's and observes their reactions. Observational Study Experiment

Example 2: Choose a Study Type 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 controller, to see which one they use the most RESTUARANTS A restaurant wants to conduct an online study in which they will ask customers whether they were satisfied with their dining experience. Experiment Survey

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

Example 3: Determining Bias Determine whether the survey question is biased or unbiased. If biased, explain your reasoning. Do you think that poisons, such as pesticides, should be sprayed on crops? Are you planning on watching the ultimate sporting event, the Super Bowl? What is your favorite type of music? Biased – They use the word poison Biased – They call it the “ultimate” sporting event Unbiased

Example 4: Identifying Flaws Identify any flaws in the design of the experiments, and describe how they could be corrected. A. 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. Result: The company concludes that the new reel is twice as effective as the old reel. Flaw: Two different lakes

Example 4 Cont. Flaw: Different playing abilities B. Experiment: A researcher wants to conduct a study to determine the effectiveness of new golf balls. They get 50 players with different playing abilities and compare their scores. They conclude that they new ball is more effective. Flaw: Different playing abilities

Example 5: Design a Study 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. Objective: To determine whether overweight cats given a new weight loss food will lose the weight Population: All overweight cats Experimental group: A group of overweight cats given the food Control group: A group of overweight cats given the food Sample procedure: Weight cats at the beginning, give each group the correct food and then weigh the cats again after a certain period of time

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. Experimental: a group where the new de-icer is used; control: a groups where a different de-icer is used. The performances of the new de-icer and the control de-icer are then compared. 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 Experimental: a group where the new de-icer is used; control: a group where a different de-icer is used Experimental: a group where a different de-icer is used; control: a group where the new de-icer is used.