Exam 1: An Introduction to Statistics and Research Design

Which of these is NOT a variable?

A medical researcher interested in asthma symptoms wanted to know how symptoms were affected in dry versus humid conditions.The researchers recruited 18 asthma patients to spend four weeks under two conditions: sleeping with a dehumidifier for two weeks to create a "dry" environment and sleeping with a humidifier for the remaining two weeks to create a "humid" environment.Patients were asked to rate their symptoms at regular intervals using a scale from "0 - no symptoms" to "20 - maximum asthma symptoms." The change in asthma symptoms from dry to humid conditions was 5.82, showing a reduction of symptoms in humid conditions.What was the descriptive statistic in this study?

The number of children per household on the U.S.Census is an example of which type of variable?

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 research design did Dr.Vallortigara employ?

The statement "100 college-aged students participated in a study examining the relationship between gender and depression" is an example of a(n) _____ in research and statistics.

Dr.Feldman was interested in the effect of Valium on motor performance.He injected 30 rats in the experimental group with a small amount of Valium and 30 rats in the control group with saline solution.Following injection, he measured the rate of bar pressing by both groups of rats.On average, rats in the control group had 800 presses per hour and rats in the experimental group had 715 presses per hour.The same testing box was used for both groups of rats, but different student assistants tested the control and experimental groups.In this example, having two different student assistants test the two groups is a(n) _____ variable.

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 sample is:

Square footage, such as that used to describe home size, is an interval variable.

A medical researcher interested in asthma symptoms wanted to know how symptoms were affected in dry versus humid conditions.The researchers recruited 18 asthma patients to spend four weeks under two conditions: sleeping with a dehumidifier for two weeks to create a "dry" environment and sleeping with a humidifier for the remaining two weeks to create a "humid" environment.Patients were asked to rate their symptoms at regular intervals using a scale from "0 - no symptoms" to "20 - maximum asthma symptoms." The change in asthma symptoms from dry to humid conditions was 5.82, showing a reduction of symptoms in humid conditions.Which statement involves an inferential statistic related to this research finding?

Holiday spending for a major electronics store is calculated for both its store-based sales (2.3 million) and online sales (1.4 million).These are both descriptive statistics.

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 is the independent variable in this study?

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.When the number of votes are actually presented, this is a(n) _____ variable.

When you read your college textbooks, you may sometimes find errors in them.If you track the number of errors based on the edition of the textbook, you might find that 1st editions have more errors than 3rd, 5th, and 10th editions.What type of variable is the edition of the text you are assessing?

_____ variables are almost always continuous.

In a within-groups research design, a participant experiences only one of the levels of the independent variable.

A community researcher wanted to explore the connection between the number of bathrooms in a house and the sale price of the house.He studied 1750 home sales in an economically diverse, medium-sized city and found that the average sale price went up by $63,000 for each full bath.What is the sample in this study?