Exam 1: Data Collection

Determine the sampling technique which is used -A travel industry researcher interviews all of the passengers on five randomly selected cruises. What sampling technique is used

Provide an appropriate response. -A student is asked to rate a guest speaker s ability to communicate on a scale of poor average good excellent. The student is to fill in a corresponding circle on a bubble form. This is an example of collecting what type of data

Distinguish Between an Observational Study and an Experiment -The personnel director at a large company would like to determine whether the company cafeteria is widely used by employees. She calls each employee and asks them whether they usually bring their own lunch, eat at the company cafeteria, or go out for lunch.

Explain the Randomized Block Design -A farmer wishes to test the effects of a new fertilizer on her potato yield. She has four equal-sized plots of land-- one with sandy soil, one with rocky soil, one with clay-rich soil, and one with average soil. She divides each of the four plots into three equal-sized portions and randomly labels them A, B, and C. The four A portions of land are treated with her old fertilizer. The four B portions are treated with the new fertilizer, and the four C s are treated with no fertilizer. At harvest time, the potato yield is recorded for each section of land. What type of experimental design is this

Explain the Completely Randomized Design -A drug company wanted to test a new acne medication. The researchers found 500 adults aged 25-35 and randomly assigned them to two groups. The first group received the new drug, while the second received a placebo. After one month of treatment, the percentage of each group whose acne symptoms decreased was recorded and compared. What type of experimental design is this

Determine the Level of Measurement of a Variable -an officer s rank in the military

A study was conducted to determine if listening to heavy metal music affects critical thinking. To test the claim, 124 subjects were randomly assigned to two groups. Both groups were administered a basic math skills exam. The first group took the exam while heavy metal music was piped into the exam room, while the second group took the exam in a silent room. The mean exam score for the first group was 81, and the mean exam score for the second group was 87. The researchers concluded that heavy metal music negatively affects critical thinking. Identify (a) the research objective, (b) the sample, (c) the descriptive statistics, and (d) the conclusions made in the study.

Explain the Steps in Designing an Experiment -What will help insure that the effect of a treatment is not due to some characteristic of a single experimental unit

Explain the Completely Randomized Design -A drug company wanted to test a new depression medication. The researchers found 700 adults aged 25-35 and randomly assigned them to two groups. The first group received the new drug, while the second received a placebo. After one month of treatment, the percentage of each group whose depression symptoms decreased was recorded and compared. How many levels does the treatment in this experiment have

Explain the Various Types of Observational Studies -Can money buy happiness A researcher wanted to determine whether there was any association between economic status and happiness. She selected a sample of 1000 adults and interviewed them. Each person was asked about their financial situation and their level of happiness was evaluated. The researcher analyzed the results to determine whether there was an association between economic status and happiness.

Explain the Sources of Bias in Sampling -A local hardware store wants to know if its customers are satisfied with the customer service they receive. The store posts an interviewer at the front of the store to ask the first 50 shoppers who leave the store, How satisfied, on a scale of 1 to 10, were you with this store s customer service Determine the type of bias.

Explain the Steps in Designing an Experiment -A salesman boasts to a farmer that his new fertilizer will increase the yield of the farmer s crops by 15%. The farmer wishes to test the effects of the new fertilizer on her corn yield. She has four equal sized plots of land one with sandy soil, one with rocky soil, one with clay-rich soil, and one with average soil. She divides each of the four plots into three equal sized portions and randomly labels them A, B and C. The four A portions are treated with her old fertilizer. The four B portions are treated with the new fertilizer. The four C portions receive no fertilizer. At harvest time, the corn yield is recorded for each section of land. What is the claim she is testing

Explain the Various Types of Observational Studies -A researcher wanted to determine whether women with children are more likely to develop anxiety disorders than women without children. She selected a sample of 900 twenty-year old women and followed them for a twenty-year period. At the start of the study, none of the women had children. By the end of the study 53% of the women had at least one child. The level of anxiety of each participant was evaluated at the beginning and at the end of the study and the increase (or decrease) in anxiety was recorded. The researchers analyzed the results to determine whether there was an association between anxiety and having children.

Determine the Level of Measurement of a Variable -the musical instrument played by a music student

Explain the Randomized Block Design -A farmer wishes to test the effects of a new fertilizer on her wheat yield. She has four equal-sized plots of land-- one with sandy soil, one with rocky soil, one with clay-rich soil, and one with average soil. She divides each of the four plots into three equal-sized portions and randomly labels them A, B, and C. The four A portions of land are treated with her old fertilizer. The four B portions are treated with the new fertilizer, and the four C s are treated with no fertilizer. At harvest time, the wheat yield is recorded for each section of land. How many levels does the treatment have in this experiment

Determine the sampling technique which is used -A writer for an art magazine randomly selects and interviews fifty male and fifty female artists. What sampling technique is used

Classify the variable as qualitative or quantitative. -the colors of book covers on a bookshelf

Explain the Matched-Pairs Design -A medical journal published the results of an experiment on depression. The experiment investigated the effects of a controversial new therapy for depression. Researchers measured the depression levels of 52 adult women who suffer moderate conditions of the disorder. After the therapy, the researchers again measured the women s depression levels. The differences between the the pre- and post-therapy depression levels were reported. Identify the experimental units.

Determine whether the quantitative variable is discrete or continuous. -the speed of a car on a Boston tollway during rush hour traffic

Explain the Randomized Block Design -When the effects of the explanatory variable upon the response variable cannot be determined, then