Exam 1: An Introduction to Statistics and Research Design

To build a sample, the U.S.Census records the number of people in a household.What type of data is this?

A researcher wanted to determine whether eating sugary cereal for breakfast increased the aggression of second graders during their morning play period.After feeding a group of 20 students sugary cereal for breakfast she observed that, on average, the students committed 4.5 aggressive behaviors during their morning play period.In this example, the population is:

Unnithan, Houser, and Fernhall (2006) were interested in whether playing the game Dance Dance Revolution (DDR) met the American College of Sports Medicine recommendations for exercise to improve cardiovascular health.Twenty-two adolescents, 10 of whom were classified as overweight and 12 of whom were not overweight, played DDR for 12 minutes.During the 12 minutes, the researchers measured each participant's heart rate.On average, the researchers found no difference between the heart rates of the two groups.Both groups' heart rates were above the minimum recommended for cardiovascular exercise.Which of these requires an inferential statistic?

A weight-management researcher was interested in whether the size of breakfast could deter overall food consumption throughout the rest of the day.He creates two breakfast groups, a 350-calorie breakfast and a 750-calorie breakfast, assigns six participants to each group, and tracks their total calories eaten in one day.Because of the detailed attention needed to accurately interview participants about their eating, he works with the high-calorie group and has his assistant interview the low-calorie group.What is the independent variable in this study?

In an experiment designed to assess the effects of disclosure of ingredients on the experience of taste, Lee, Frederick, and Ariely (2006) approached patrons at a local pub and asked them to taste and rate a new beer: the MIT Brew.Some participants were told about the secret ingredient in the beer (a few drops of balsamic vinegar) either before tasting (before condition) or after tasting but before rating (after condition).Other participants were not told anything regarding the secret ingredient (not told condition).Which aspect of this study is an operational definition of the dependent variable?

A test with low reliability cannot have good validity.

A New York Times article published on April 24, 2007, reported the research of Dr.Vallortigara, a neuroscientist at the University of Trieste, Italy.In this study, Dr.Vallortigara assessed whether a dog's tail wags in a preferred direction in response to positive as opposed to negative stimuli.First, Dr.Vallortigara recruited 30 dogs that were family pets.While filming a dog's tail from above, he allowed the dog to view (through a slot in its cage) its owner, an unfamiliar human, a cat, and an unfamiliar dominant dog.The study found that dogs' tails wagged to the right for the owner and to the left for the unfamiliar dominant dog.What type of measure was the dependent variable in this study?

Prof.Martin was interested in which of two popular statistics textbooks (Statistics: It Will Change Your Life and Statistics: Bigger, Better, Stronger) was better for students.Prof.Martin compared the two texts by assigning one text to a section of statistics taught by Prof.Miller from 10 to 11 a.m.on Monday, Wednesday, and Friday, and the other text to a section of statistics taught by Prof.Mervin from 7 to 10 p.m.on Wednesday evenings.At the end of the term, all students took the same comprehensive test.Students to whom Statistics: Bigger, Better, Stronger was assigned performed better on the test than did students to whom Statistics: It Will Change Your Life was assigned.Therefore, Prof.Martin concluded that the former textbook was the better one.Which of the following is NOT a potential confounding variable in this study?

If a test is reliable, then we know that it is valid.

Variables that can take on only certain numbers such as whole numbers are:

The Beck Depression Inventory is a scale intended to measure depression levels, with higher scores indicating higher levels of depression.If the Beck test is a valid measure of depression, we would expect that:

Inferential statistics allow a researcher to:

In the Coke/Pepsi Challenge, tasters try to identify regular and diet versions of these popular beverages under "blind" conditions, where they can't see the two products.How many levels are there to the independent variable?

In a student election, five people run for student body president.The votes are tallied to create a list of candidates from most to least popular.The number of votes is then removed so that a list of candidates from most to least popular is presented.This is a(n) _____ variable.

In order to assess the effect of pet ownership on health, a researcher surveys 150 people who own pets and 150 people who do not own pets.The sample being studied is:

A variable that consists of separate specific categories for which there are no values between categories is:

Inferential statistics summarize a group, while descriptive statistics help us make estimates about a larger population.

A variable that is systematically linked with the factor a researcher believes is causing the overall effect in your research is called the _____ variable.The presence of such a variable can prevent the researcher from knowing what is really causing the effect.

Unnithan, Houser, and Fernhall (2006) were interested in whether playing the game Dance Dance Revolution (DDR) met the American College of Sports Medicine recommendations for exercise to improve cardiovascular health.Twenty-two adolescents, 10 of whom were classified as overweight and 12 of whom were not overweight, played DDR for 12 minutes.During the 12 minutes, the researchers measured each participant's heart rate.On average, the researchers found no difference between the heart rates of the two groups.Both groups' heart rates were above the minimum recommended for cardiovascular exercise.What is the sample in this study?

A researcher studies year in college, first through fourth year, and its relation to academic motivation.To get the most detail out of her measures, she assesses each student in both the fall and spring semesters of each their four years in school.She finds that students have increasingly higher motivation from their first to fourth year, with a trailing off in the last semester.What is the dependent variable in this study?