Chapter 1: Intro to Research Statistics
Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
What additional information is obtained from measurements on a ratio scale compared to measurements on an interval scale? Magnitude of difference between two measurements Direction of difference (greater or less) between two measurements Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
Magnitude of difference between two measurements
What additional information is obtained from measurements on an interval scale compared to measurements on an ordinal scale? Direction of difference (greater or less) between two measurements Magnitude of difference between two measurements Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
Direction of difference (greater or less) between two measurements
four scales of measurement were introduced in this chapter, from simple classification on a nominal scale to the more informative measurements from a ratio scale. What additional information is obtained from measurements on an ordinal scale compared to measurements on a nominal scale? Magnitude of difference between two measurements Direction of difference (greater or less) between two measurements Comparison of the magnitudes of two measurements (such as one being twice as large as the other)
Operational definition of a variable
identifies a measurement procedure (a set of operations) for measuring an external behavior and uses the resulting measurements as a definition and a measurement of a hypothetical construct. Note that an operational definition has two components: First, it describes a set of operations for measuring a construct. Second, it defines the construct in terms of the resulting measurements
sample`
is a set of individuals selected from a population, usually intended to represent the population in a research study.
parameter
is a value—usually a numerical value—that describes a population. A parameter is usually derived from measurements of the individuals in the population.
statistic
is a value—usually a numerical value—that describes a sample. A statistic is usually derived from measurements of the individuals in the sample.
ratio scale
is an interval scale with the additional feature that a score of zero indicates none of the variable being measured. With a ratio scale, ratios of numbers do reflect ratios of magnitude
Sampling error
is the naturally occurring discrepancy, or error, that exists between a sample statistic and the corresponding population parameter.
population
is the set of all the individuals of interest in a particular study.
discrete, continuous, discrete, continuous
state where each variable is a continuous or discrete variable? age = annual income = number of dependents = social security number =
continuous variable
there are an infinite number of possible values that fall between any two observed values. A continuous variable is divisible into an infinite number of fractional parts.
correlational method
two different variables are observed to determine whether there is a relationship between them.
anxious, hunger, intelligence
what are some examples of constructs?
discrete variables are variables which have a separate, indivisible categories and continuous variables tend to have many possible values
what is the difference between discrete and continuous variables?
in the interval scale there is a arbitrary zero point in which it doesn't mean that it is really zero like 0F doesn't mean there is no temperature but the ratio scale there is a meaningful zero point so a 0 really means nothing
what is the main difference between interval scale and rate scale?
defines a construct in terms of external behaviors that can be observed and measured
what is the operational definition?
experimental method,
In the _______________ _________ one variable is manipulated while another variable is observed and measured. To establish a cause-and-effect relationship between the two variables, an experiment attempts to control all other variables to prevent them from influencing the results.
To make general conclusions about populations using sample data
Inferential statistics are generally used for which of the following? Check all that apply. To make general conclusions about populations using sample data To simplify and summarize data To describe dependent variables only To describe independent variables only
statistic
The average number that the researcher calculated is an example of a __________ .
To demonstrate the existence of a cause-and-effect relationship between two variables
The goal of an experimental research study is which of the following?
To demonstrate the existence of a cause-and-effect relationship between two variables
The goal of an experimental research study is which of the following? To make an observation without manipulating any variables To demonstrate the existence of a cause-and-effect relationship between two variables To make an observation to determine the correlation between two variables To make an observation to determine the relationship among several variables
ratio, continuous, ratio, discrete, ratio, discrete, nominal, discrete
A tax form asks people to identify their age, annual income, number of dependents, and social security number. For each of these four variables, identify the scale of measurement that probably is used and identify whether the variable is continuous or discrete. Variable scale type age ___1____ ____2_____ annual income ___3____ ____4___ number of dependents ____5__ _______6____ social security # ____7___ ______8____
Number of correct answers on the test, Discrete, Ratio
Ackerman and Goldsmith (2011) compared learning performance for students who studied material printed on paper versus students who studied the same material presented on a computer screen. All students were then given a test on the material and the researchers recorded the number of correct answers. Identify the dependent variable for this study. Number of students who studied the computer screen Number of correct answers on the test Total number of questions on the test Is the dependent variable discrete or continuous? Not enough information to answer this question Discrete Continuous What scale of measurement (nominal, ordinal, interval, or ratio) is used to measure the dependent variable? Interval Ordinal Ratio Nominal
(∑X)²
Add the scores and square the sum. (∑X)² ∑X² 2(∑X) ∑(X)²
Tattoo or no tattoo, Nominal, Rating of attractiveness, Ordinal
There is some evidence that people with a visible tattoo are considered to be less attractive than are people without a visible tattoo. Resenhoeft, Villo, and Wiseman (2008) showed one group of students a color photograph of a 24-year-old woman with a tattoo of a dragon on her arm. A second group of students was shown the same photograph but with the tattoo removed. Each participant was asked to rate the attractiveness of the woman in the photograph. Identify the independent variable for this study. Number of attractive students Tattoo or no tattoo Number of sentences shown Number of students with tattoos What scale of measurement is used for the independent variable? Ordinal Nominal Interval Ratio Identify the dependent variable for this study. Rating of attractiveness Number of students with tattoos Tattoo or no tattoo Number of attractive students What scale of measurement is used for the dependent variable? Nominal Ordinal Ratio Interval
manipulate an indenpendent variable and control extraneous variables
To accomplish the goal, an experiment must do which of the following?
Manipulate an independent variable, Control extraneous variables
To accomplish the goal, an experiment must do which of the following? Check all that apply. Manipulate several variables Control an independent variable Manipulate an independent variable Control extraneous variables
∑(X - 2)
Subtract 2 points from each score and then add the resulting values. ∑X - 2 ∑(X - 2)² (∑X)² - 2 ∑(X - 2)
population, sample
A parameter is a characteristic, usually a numerical value, that describes a _________. A statistic is a characteristic, usually numerical, that describes a ________-.
A characteristic of a population
A parameter is which of the following? Check all that apply. A characteristic of a sample Always a dependent variable A characteristic of a population Always an independent variable
This is not an experiment., The researchers are not manipulating an independent variable, but comparing preexisting groups of US and Canadian students.
A research study comparing alcohol use for college students in the United States and Canada reports that more Canadian students drink but US students drink more (Kuo, Adlaf, Lee, Gliksman, Demers, and Wechsler, 2002). Is this an experimental study or a nonexperimental study? This is not an experiment. This is an experiment. Which of the following explanations for your answer is correct? The researchers are not manipulating an independent variable, but comparing preexisting groups of US and Canadian students. The researchers are manipulating the likelihood of students drinking. The researchers are not manipulating an independent variable, but comparing preexisting groups of students who drink more or less. The researchers are manipulating the amount students drink.
The 100 students who were measured in the study
A researcher is interested in the texting habits of high school students in the United States. The researcher selects a group of 100 students, measures the number of text messages that each individual sends each day, and calculates the average number for the group. Identify the sample in this study. The entire set of high school students in the United States The entire set of text messages sent by high school students in the United States The 100 students who were measured in the study The entire set of text messages sent by the 100 students who were measured in the study
The entire set of high school students in the United States
A researcher is interested in the texting habits of high school students in the United States. The researcher selects a group of 100 students, measures the number of text messages that each individual sends each day, and calculates the average number for the group. Identify the population in this study. The entire set of text messages sent by the 100 students who were measured in the study The entire set of high school students in the United States The 100 students who were measured in the study The entire set of text messages sent by high school students in the United States
A characteristic of a sample
A statistic is which of the following? Check all that apply. Always an independent variable A characteristic of a population Always a dependent variable A characteristic of a sample
By giving participants a multiple choice questionnaire on which the answers indicate how they behave or feel in situations for which honesty might have an influence, By asking a series of specific questions and measuring participants' physiological responses using a polygraph
Describe how honesty might be measured and defined using an operational definition. Check all that apply. By asking participants to describe an incident in which they felt they were being particularly honest By giving participants a multiple choice questionnaire on which the answers indicate how they behave or feel in situations for which honesty might have an influence By asking participants to rank their fellow participants in terms of honesty By asking participants to write an essay describing what part honesty plays in their lives By asking a series of specific questions and measuring participants' physiological responses using a polygraph
It has only one group of individuals., It measures two (or more) different variables for each individual.
Describe the data for a correlational research study and explain how these data are different from the data obtained in experimental and nonexperimental studies, which also evaluate relationships between two variables. A correlational study satisfies which of the following conditions? Check all that apply. It has more than one group of individuals. It measures two (or more) different variables for each individual. It measures only one variable for each individual. It has only one group of individuals.
The entire group of individuals of interest
Define the terms population and sample, and explain the role of each in a research study. What is a population? A relatively large group selected to include as many individuals of interest as possible A relatively small group selected from the individuals of interest The entire group of individuals of interest
A relatively small group selected from the individuals of interest
Define the terms population and sample, and explain the role of each in a research study. What is a sample? A relatively large group selected to include as many individuals of interest as possible A relatively small group selected from the individuals of interest The entire group of individuals of interest
By giving participants a multiple choice questionnaire on which the answers indicate how they behave or feel in situations for which honesty might have an influence & By asking a series of specific questions and measuring participants' physiological responses using a polygraph
Describe how honesty might be measured and defined using an operational definition. Check all that apply. By asking participants to describe an incident in which they felt they were being particularly honest By giving participants a multiple choice questionnaire on which the answers indicate how they behave or feel in situations for which honesty might have an influence By asking participants to rank their fellow participants in terms of honesty By asking participants to write an essay describing what part honesty plays in their lives By asking a series of specific questions and measuring participants' physiological responses using a polygraph
The independent variable is whether the motivational signs were posted, and the dependent variable is the amount of use of the stairs.,Nominal
Ford and Torok (2008) found that motivational signs were effective in increasing physical activity on a college campus. Signs such as "Step up to a healthier lifestyle" and "An average person burns 10 calories a minute walking up the stairs" were posted by the elevators and stairs in a college building. Students and faculty increased their use of the stairs during times that the signs were posted compared with times when there were no signs. Identify the independent and dependent variables for this study. The independent variable is the time when the motivational signs were posted, and the dependent variable is the amount of use of the stairs. The independent variable is the ratio of students to faculty using the stairs, and the dependent variable is the length of time the signs were posted. The independent variable is the amount of use of the stairs, and the dependent variable is whether the motivational signs were posted. The independent variable is whether the motivational signs were posted, and the dependent variable is the amount of use of the stairs. What scale of measurement is used for the independent variable? Interval Ordinal Ratio Nominal
This is not an experiment., The researchers are not manipulating an independent variable, but comparing preexisting groups of students who experience more or less video game violence.
Gentile, Lynch, Linder, and Walsh (2004) surveyed over 600 8th- and 9th-grade students asking about their gaming habits and other behaviors. Their results showed that the adolescents who experienced more video game violence were also more hostile and had more frequent arguments with teachers. Is this an experimental study or a nonexperimental study? This is not an experiment. This is an experiment. Which of the following explanations for your answer is correct? The researchers are not manipulating an independent variable, but comparing preexisting groups of students who experience more or less video game violence. The researchers are manipulating the level of video game violence the students are experiencing. The researchers are not manipulating an independent variable, but comparing preexisting groups of students who show more or less hostility toward teachers. The researchers are manipulating the students' level of hostility.
Color of the T-shirt (red versus not red), Size of tip, Nominal
Guéguen and Jacob (2012) asked female restaurant wait staff to wear different colored T-shirts on different days for a six-week period and recorded the tips left by male customers. The results show that male customers gave significantly bigger tips when the wait persons were wearing red. What is the independent variable for this study? Number of male customers who left a tip Day on which the wait person wore red Size of tip Color of the T-shirt (red versus not red) What is the dependent variable for this study? Size of tip Number of male customers who left a tip Color of the T-shirt (red versus not red) Day on which the wait person wore red What scale of measurement is used for the independent variable? Ratio Nominal Ordinal Interval
An internal attribute or characteristic that cannot be observed directly
Honesty is a hypothetical construct rather than a concrete variable because it is: An external attribute or characteristic A characteristic that can be observed directly An indirect method for measuring and defining an attribute An internal attribute or characteristic that cannot be observed directly
naturally occurring, sample statistic, population parameter
Sampling error is the ________ ______ discrepancy between a ___________ and the corresponding _____________.
∑X²
Square each score and then add the squared values. ∑X² ∑(2X + 1) (∑X)² ∑(X + 2)²
To simplify and summarize data
Statistical methods are classified into two major categories: descriptive and inferential. Describe the general purpose for the statistical methods in each category. Descriptive statistics are generally used for which of the following? Check all that apply. To make general conclusions about populations using sample data To describe dependent variables only To describe independent variables only To simplify and summarize data
The type of word being shouted, Pain tolerance
Stephens, Atkins, and Kingston (2009) conducted an experiment in which participants were able to tolerate more pain when they were shouting their favorite swear words than when they were shouting neutral words. Identify the independent and dependent variables for this study. The independent variable is which of the following? Level of pain being applied Pain tolerance The type of word being shouted The participant's favorite swear word The dependent variable is which of the following? The participant's favorite swear word Pain tolerance Level of pain being applied The type of word being shouted
∑(X - 1)²
Subtract 1 point from each score and square the resulting values. Then add the squared values. (∑X)² - 1 ∑X² - 1 ∑(X² - 1) ∑(X - 1)²
population, population, too large for every individual to participate in the research study, sample, sample, generalized to the population .
The research begins with a question about then ________ . However, the _________ is usually __________________________________________ . Therefore, the individuals in the ________ are the actual participants, and the results from the _______ are then_________ _________ _________ __________
This is not an experiment because no independent variable is manipulated. The researchers are comparing two preexisting groups of individuals.
The results of a recent study showed that children who routinely drank reduced fat milk (1% or skim) were more likely to be overweight or obese at age 2 and age 4 compared to children who drank whole or 2% milk (Scharf, Demmer, and DeBoer, 2013). Is this an example of an experimental study or of a nonexperimental study? This is an experiment. The independent variable the researchers are manipulating is whether the child drinks reduced fat milk. This is not an experiment because no independent variable is manipulated. The researchers are comparing two preexisting groups of individuals.
Constructs
are internal attributes or characteristics that cannot be directly observed but are useful for describing and explaining behavior.
Descriptive statistics
are statistical procedures used to summarize, organize, and simplify data.
Inferential statistics
consist of techniques that allow us to study samples and then make generalizations about the populations from which they were selected.
ordinal scale
consists of a set of categories that are organized in an ordered sequence. Measurements on an ordinal scale rank observations in terms of size or magnitude.
nominal scale
consists of a set of categories that have different names. Measurements on a nominal scale label and categorize observations, but do not make any quantitative distinctions between observations.
interval scale
consists of ordered categories that are all intervals of exactly the same size. Equal differences between numbers on scale reflect equal differences in magnitude. However, the zero point on an interval scale is arbitrary and does not indicate a zero amount of the variable being measured.
discrete variable
consists of separate, indivisible categories. No values can exist between two neighboring categories.
