chapter 12-psych 2301

True or false: The absolute size of the Pearson r is the coefficient that indicates the direction of the relationship between variables.

False

_____ use a line to represent the distribution of frequencies of scores.

Frequency polygons

_____ variables have detailed quantitative properties.

Interval scale

Identify the accurate comparison between interval scales and ordinal scales.

Interval scales allow for more sophisticated statistical treatments than do ordinal scales.

Identify the accurate statements about the standard deviation. (Check all that apply.)

It is large when most people have scores that lie farther from the mean value. It is small when most people have similar scores close to the mean.

In scientific reports, the median is abbreviated as _____.

Mdn

In a Pearson r value, the direction of the relationship between variables is signified by _____.

the sign attached to the value

The standard deviation is the square root of _____.

the variance

A similarity between ratio scale variables and interval scale variables is that _____.

they use the same statistical procedures to analyze data

True or false: The range is a measure of variability.

true

True or false: When describing and analyzing the results of research investigations, most research focuses on the study of relationships between variables.

true

Which of the following scenarios uses the ordinal scale of measurement?

Teachers ranking students according to their perception of students' interest in class

As _____, it is important to construct a scatterplot in addition to looking at the magnitude of a correlation coefficient.

a relationship is likely to be curvilinear

The advantage of reporting effect size is that it provides us with _____.

a scale of values that is consistent across all types of studies

Comparing group percentages when describing the results of a study is effective when _____.

a variable is nominal

The mean of a set of scores is an appropriate indicator of central tendency only when scores are measured _____.

on an interval or ratio scale

A partial correlation is a correlation between two variables of interest with _____.

the influence of the third variable removed from the original correlation

The median or mode can be a better indicator of central tendency than the mean if _____.

the mean is biased by a few unusual scores

Which value of a Pearson r indicates that there is no relationship between the variables?

0.00

A separate and distinct bar for each piece of information is used when graphing frequency distributions in __________ graphs.

Bar

Identify the basic ways of describing the results of research investigations depending on the way the variables are studied. (Check all that apply.)

Correlating scores of individuals on two variables Comparing group percentages

_____ refers to the strength of association between variables.

Effect size

_____ ______variables have both equal intervals and an absolute zero point that indicates the absence of the variable being measured.

Ratio Scale

The criterion variable The predictor variable

Refers to some future behavior that researchers are interested in Refers to a person's score on a variable that helps predict future behavior

_____ are calculations used to predict a person's score on one variable when that person's score on another variable is already known.

Regression equations

x axis y axis

The levels of an independent variable Dependent variable values

Identify the measures of central tendency. (Check all that apply.)

The median The mean

Which of the following is a measure of variability that indicates the difference between the highest score and the lowest score in a set of scores?

The range

Which of the following is a measure of variability that indicates the average deviation of scores from the mean?

The standard deviation

Identify the types of information about the relationship between variables provided by the Pearson r. (Check all that apply.)

The strength of the relationship The direction of the relationship

Identify the statistics that are needed to describe data collected as part of a study. (Check all that apply.)

Variability Central tendency

Bar graphs Line Graphs

When the values on the x axis are nominal categories When the values on the x axis are numeric

Which of the following is a general form of a multiple regression equation?

Y = a + b1X1 + b2X2 + ... + bnXn

With Y as the score one wishes to predict, X as the known score, a as a constant, and b as a weighting adjustment factor, the general form of a regression equation is _____.

Y = a + bX

Research using structural equation modeling leads to _____.

a better understanding of the complex networks of relationships among variables

When analyzing the results of an experiment, researchers start by constructing a _____.

frequency distribution of the data

A _____ statistic describes what the sample as a whole, or on the average, is like.

central tendency

A measure of variability is a number that _____.

characterizes the amount of spread in a distribution of scores

An experiment is conducted to study the effect of watching violent movies on individual behavior. One group of participants is asked to watch a violent movie and then play a video game. The second group of participants is asked to play the video game without watching the movie. The researchers then observe how the individuals in the two groups behave with each other while playing the video game and record the number of times the participants show aggressive behavior. In this scenario, the results will most likely be described by _____.

comparing group means

A study analyzed the interest of male and female students in playing baseball. The study surveyed 100 female and 90 male students. When describing the results, the study reported that 60% of the female students liked baseball in comparison with 80% of the male students. In this scenario, the study describes the results by _____.

comparing group percentages

When using bars to display a frequency distribution for a quantitative variable, the scale values are _____.

continuous

When researchers have an interval or ratio scale of measurement, the results of research investigations are described by _____.

correlating individual scores

A numerical index of the strength of relationship between variables is called a(n) ____.

correlation coefficient

The levels of nominal scale variables are _____.

different categories

An application of structural equation modeling is to _____.

evaluate how closely the obtained data fit the specified model

A _____ indicates the number of individuals who receive each possible score on a variable.

frequency distribution

A _____ uses bars to display a frequency distribution for a quantitative variable.

histogram

It is sometimes preferable to report the squared value of a correlation coefficient because _____.

it changes the obtained value to a percentage

Correlation coefficients are very important because a researcher needs to ___.

know how strongly variables are related to one another

The Pearson product-moment correlation coefficient (r) is designed to detect only _____.

linear relationships

If the range of possible values of variables is restricted, the _____.

magnitude of the correlation coefficient is reduced

Descriptive statistics of research scores allow researchers to _____.

make precise statements about the obtained data

The _____ of a set of scores is obtained by adding all the scores and dividing by the number of scores.

mean

In descriptive statistics, the score that divides a group in half is called the _____.

median

In descriptive statistics, the _____ is the most frequent score and the only measure of central tendency that is appropriate if a nominal scale is used.

mode

A(n) _____ is an expected pattern of relationships among a set of variables.

model

A technique that is used to combine a number of predictor variables to increase the accuracy of prediction of a given criterion or outcome variable is called _____.

multiple correlation

The levels of _____ variables have no numerical, quantitative properties.

nominal scale

Variables with _____ levels exhibit minimal quantitative distinctions.

ordinal scale

_____ _____ is a technique that provides a way of statistically controlling third variables.

partial correlation

Statistical analysis provides _____, which are similar to the standardized weights derived in regression equations.

path coefficients

The squared value of a correlation coefficient is sometimes referred to as the _____.

percent of shared variance between two variables

When correlating individual scores to describe the results of research investigations, individuals are measured on two variables, and each variable has a _____.

range of numerical values

Comparing group means is a way of describing the results of research investigations when experiments involve _____.

ratio scale variables

When researchers are interested in predicting some future behavior on the basis of a person's score on some other variable in regression equations, it is first necessary to demonstrate that there is a _____.

reasonably high correlation between the criterion and predictor variables

Pie charts are particularly useful when _____.

representing nominal scale information

The problem of _____ occurs when the individuals in a sample are very similar on the variable being studied.

restriction of range

A graph in which each pair of scores is plotted as a single point in a diagram is called a _____.

scatterplot

The Pearson r provides information about the _____.

strength and direction of the relationship between variables

Path coefficients indicate the _____.

strength of a relationship

In a Pearson r value, the nearer a correlation is to 1.00 (plus or minus), the _____.

stronger is the relationship between the variables

The general term used to refer to a complex set of techniques used to examine models that specify a set of relationships among variables using quantitative nonexperimental methods is _____.

structural equation modeling (SEM)