Exam 1: Data Collection

Distinguish Between an Observational Study and an Experiment -Experiments assist the researcher in isolating the causes of the relationships that exist between two variables.

Explain the Sources of Bias in Sampling -Which type of bias occurs because we do not obtain complete information about a population

Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 130 students and carefully recorded their parking times. Identify the population of interest to the university administration.

Determine the Level of Measurement of a Variable -ranking (first place, second place, etc.) of contestants in a singing competition

Explain the Matched-Pairs Design -A medical journal published the results of an experiment on anorexia. The experiment investigated the effects of a controversial new therapy for anorexia. Researchers measured the anorexia levels of 72 adult women who suffer moderate conditions of the disorder. After the therapy, the researchers again measured the women s anorexia levels. The differences between the the pre- and post-therapy anorexia levels were reported. What type of experimental design is this

Distinguish Between an Observational Study and an Experiment -A pollster obtains a sample of students and asks them how they will vote on an upcoming referendum.

Determine the sampling technique which is used -Based on 12,500 responses from 46,500 questionnaires sent to all its members, a major medical association estimated that the annual salary of its members was $111,000 per year. What sampling technique was used

Determine the Level of Measurement of a Variable -weight of rice bought by a customer

Determine whether the quantitative variable is discrete or continuous. -the number of bottles of juice sold in a cafeteria during lunch

Distinguish Between an Observational Study and an Experiment -Observational studies are not as useful as experiments to learn about the characteristics of a population.

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 95 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. What is the treatment in this experiment

Obtain a Simple Random Sample -Select a random sample of five state capitals from the list below using the two digit list of random numbers provided. Begin with the uppermost left random number and proceed down each column. When a column is complete, use the numbers at the top of the next right column and proceed down that column. State Capitals 1 Abany, NY 11 Charleston, WV 21 Hartford, CT 31 Madison, WI 41 Richmond, VA 2 Annapolis, MD 12 Cheyenne, WY 22 Helena, MT 32 Mortgomery, AL 42 Sacramento, CA 3 Atlanta, GA 13 Columbia, SC 23 Honolulu, HI 33 Mortpelier, VT 43 Salem, OR 4 Augusta, ME 14 Columbus, OH 24 Indianapolis, IN 34 Nashville, TN 44 Salt Lake City, UT 5 Austin, TX 15 Concord, NH 25 Jacksor, MS 35 Oklahoma City, OK 45 Santa Fe, NM 6 Baton Rouge, LA 16 Denver, CO 26 Jefferson City, MO 36 Olympia, WA 46 Springfield, IL 7 Bismarck, ND 17 Des Moines, IA 27 Juneau, AK 37 Phoenix, AZ 47 St. Paul, MN 8 Boise, ID 18 Dover, DE 28 Lansing, MI 38 Pierre, SD 48 Tallahassee, FL 9 Boston, MA 19 Frankfort, KY 29 Lincoln, NE 39 Providence, RI 49 Topeka KS 10 Carson City, NV 20 Hamisburg, PA 30 Little Rock, AR 40 Raleigh, NC 50 Trentor, NJ 46 81 17 60 92 59 40 9 53 78 45 14 53 78 8 43 3 99 46 86 41 42 36 95 39 14 16 59 84 18 5 48 45 41 77 91 11 43 76 28

Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 100 students and carefully recorded their parking times. Identify the sample of interest to the university administration.

Determine the sampling technique which is used -An education researcher randomly selects 85 of the nation s junior colleges and interviews all of the professors at each school. What sampling technique was used

Determine the Level of Measurement of a Variable -the native language of a tourist

Explain the Matched-Pairs Design -A medical journal published the results of an experiment on insomnia. The experiment investigated the effects of a controversial new therapy for insomnia. Researchers measured the insomnia levels of 48 adult women who suffer moderate conditions of the disorder. After the therapy, the researchers again measured the women s insomnia levels. The differences between the the pre- and post-therapy insomnia levels were reported. How many levels does the treatment have in this experiment

A manufacturer of cellular phones has decided that an assembly line is operating satisfactorily if less than 0.0 2% of the phones produced per day are defective. To check the quality of a day s production, the company decides to randomly sample 40 phones from a day s production to test for defects. Define the population of interest to the manufacturer.

Determine the Level of Measurement of a Variable -an evaluation received by a physics student (excellent, good, satisfactory, or poor).

Explain the Sources of Bias in Sampling -A researcher wants to study the effects of advertising by female models upon high school boys in small Midwestern towns. The research methodology calls for selecting several small Midwestern towns that have high schools. What is the frame for this study

Determine the sampling technique which is used -The names of 20 employees are written on 20 cards. The cards are placed in a bag, and three names are picked from the bag. What sampling technique was used