1.2 What is the difference between a sample and a population?

1.6 What is the relation between an independent variable and a dependent variable?

1.8 What is the difference between reliability and validity, and how are the two concepts related?

1.12 What is the difference between a between-groups research design and within-groups research design?

1.20 In the fall of 2008, the US stock market plummeted

several times, with grave consequences for the world

economy. A researcher might assess the economic effect

this situation had by seeing how much money people

saved in 2009. That amount could be compared to the

amount people saved in more economically stable years.

How might you operationalize the economic implications at a national level?

1.22 A study of the effects of skin tone (light, medium, and

dark) on the severity of facial wrinkles in middle age

might be of interest to cosmetic surgeons.

a. What would the independent variable be in this

study?

b. What would the dependent variable be in this study?

c. How many levels would the independent variable

have?

1.30 Operationalizing variables and rap statistics: The

Web site Rap Genius analyzes rap music using what

they call RapMetrics (http://rapgenius.com/posts/63

Introducing-rapmetrics-the-birth-of-statistical

analysis-of-rap-lyrics). It has developed a measure called

rhyme density, which is the proportion of all syllables

that are part of the rhyme. Eminem's Without Me, for

example, has a rhyme density of 0.49 (49%) because

almost half of the lyrics are part of the rhyme, whereas

Notorious B.I.G. Juicy only has a rhyme density of

0.23 (23%). The people behind Rap Genius say, "Over

the course of a career, the rappers with the highest

rhyme densities are basically the best technical rappers.

a. How does Rap Genius operationalize the best rapper?

b. List at least three other variables that might be con

sidered in determining the best rapper.

c. Across all songs, MF Doom came in first with an

overall rhyme density of 0.44, and Cam'ron came

in second with a rhyme density of 0.41. What kind

of variable is the ranking, and what kind of variable

is the rhyme density?

d. Rap Genius summarized its rhyme density

discussion by saying:"MF Doom surprised us a lit

tle. First the big New Yorker profile and now this..

it's too much! Cam'ron is much more culturally rel

evant and interesting (plus he doesn't need to wear

a mask, he's naturally silly), so we at RapMetrics

consider him the G.O.A.T.Greatest of all time] MC

Irapper] overall."Rap Genius, therefore, changed

operational definition a bit. What has it added to it

operational definition of the overall G.O.A.T. MC

1.34 Experimental versus correlational research and

culture: A researcher interested in the cultural values

of individualistic and collectivist societies collects data

on the rate of relationship conflict experienced by 32

people who test high for individualism and 37 people

who test high for collectivism.

a. Is this research experimental or correlational?

Explain.

b. What is the sample?

c. Write a possible hypothesis for this researcher.

d. How might we operationalize relationship

conflict?

2.6 What are the typical labels for the x-axis and the y-axis

in a histogram?

2.10 What is a normal distribution

2.14 Convert the following to percentages: 63 out of 1264;

2 out of 88.

2.20 On a test of marital satisfaction, scores could range from

to 27.

a. What is the full range of data, according to the

calculation procedure described in this chapter?

b. What would the interval size be if we wanted six intervals?

c. List the six intervals

Putting It All Together 2.38 Frequencies, distributions, and numbers of friends: A college student is interested in how many friends the average person has. She decides to count the number of people who appear in photographs on display in dorm rooms and offices across campus. She collects data on 84 students and 33 faculty members. The data are presented below. 60 beduong 5 508519 50 anlogbun . Cardnom 40 to noneding Frequency 30 nozomib bas ogede 20 of Svines rash ord bloo 10 0 3 9 5 21 27 imib yonoupoil mort and Number of people pictured OAS no. 86.S sabroad mi bodhoeob sasb abrisint ord to a. What kind of visual display is this? b. Estimate how many people have fewer than 6 peo- ple pictured. c. Estimate how many people have more than 18 people pictured. d. Can you think of additional questions you might ask after reviewing the data displayed here? e. Below is a subset of the data described here. Cre- ate a grouped frequency table for these data, using seven groupings. 1 5 3 9 13 0 18 15 3 3 5 7 7 7 11 3 12 20 16 4 17 15 16 10 6 8 87 3 1744 CHAPTER 2 . Frequency Distributions f. Create a histogram of the grouped data from (e). g. Describe how the data depicted in the original graph and the histogram you created in part (f) are distributed