Population and Sample
Descriptive vs. Inferential Statistics
Variables
Experimental Design
Wildcard
100
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:
the 20 students the researcher observed.
100
a single number or group of numbers that organize, summarize, and communicate a group of numerical observations defines what type of statistic?
descriptive
100
The variable that is manipulated or observed in order to determine its effects on another variable is the _____ variable.
independent
100
A correlation measures the relationship among _____ or more variables.
two
100
What research technique is crucial to drawing the conclusion that the independent variable caused the change in the dependent variable?
random assignment to groups
200
a subset, or smaller collection, of observations from the overall group of interest describes a
sample
200
using data to make general estimates about the overall group of interest describes which statistic?
inferential
200
A variable for which there is an infinite number of values between any two points on the scale is:
continuous.
200
every participant in the study has an equal chance of being assigned to any condition or level of the independent variable.
Random assignment refers to a situation in which:
200
When a test measures what it is intended to measure, the test is said to be:
valid.
300
An elementary school teacher is interested in the relation between sugar consumption and activity level in preschool children. The teacher gives 30 preschool children from Preppy Preschool Playland 0 milligrams, 20 milligrams, or 50 milligrams of sucrose (sugar) in a breakfast drink. She then observes their behavior for 30 minutes during their morning outdoor play period and codes their activity level. In this example, the sample is:
30 preschool children.
300
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 descriptive statistic is:
the 4.5 aggressive behaviors.
300
The outcome variable that we expect to change with changes in the independent variable is the _____ variable.
dependent
300
(True/False) In a between-groups research design, a participant experiences one and only one of the levels of the independent variable.
TRUE
300
A researcher studies length of time 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 of their four years in school. She finds that students have increasingly higher motivation from their first semester to their seventh semester (the start of their fourth year), with a trailing off in the last semester. What is the independent variable in this study?
semester in school
400
the entire group of interest about which we want to make conclusions.
population
400
A community researcher wanted to explore the connection between the number of bathrooms in a house and the sale price of the house. She 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 descriptive statistic in this study?
average increase in sale price of $63,000 per bathroom
400
A person's grade point average on a scale from 0 to 4.0 is a(n) _____ variable.
ratio
400
(True/False) In a within-groups research design, a participant experiences more than one of the levels of the independent variable.
TRUE
400
(True/False) Mattress size, including twin, full, queen, king, and California king, is a nominal variable.
FALSE
500
Twenty-two adolescents were split into two separate groups. 10 of whom were classified as overweight were in group 1 and 12 of whom were not overweight were in group 2, 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 population in this study?
all adolescents, both overweight and not overweight, who play DDR
500
Researchers reported the results of a study in which 195 college students completed a happiness scale (from 1 to 7) just before taking a midterm exam. On this scale, 1 corresponded to very unhappy and 7 to very happy. On average, the students rated their happiness as 6.18. In this study, which of these would require an inferential statistic?
the conclusion that college students, on average, are rather happy prior to taking midterm exams
500
A researcher was interested in the effects of gender on attitudes toward women in leadership positions. The researcher surveyed a group of individuals, 12 of whom were men and 12 of whom were women. In this example, what is the dependent variable?
participants' attitudes toward women in leadership positions
500
examining observations that do not fit the overall pattern of data, in an effort to understand the factors that influence the dependent variable describes what type of analysis?
outlier analysis
500
People debate whether standardized tests, such as the ACT and SAT, are predictors of college performance. This is essentially a debate about:
validity
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