EOCP Chapter 1 Introduction to Statistics

Use summation notation to express each of the following calculations. 1. Add the scores and square the sum. 2. Square each score and then add the squared values. 3. Subtract 2 points from each score and then add the resulting values. 4. Subtract 1 point from each score and square the resulting values. Then add the squared values.

1. (∑X)² 2. ∑X² 3. ∑(X - 2) 4. ∑(X - 1)²

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. 1. A correlational study satisfies which of the following conditions? Check all that apply.

1. -It has only one group of individuals. -It measures two (or more) different variables for each individual.

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. 1. Age 2. Annual income 3. Number of dependents 4. Social security number

1. Ratio/Continuous 2. Ratio/Discrete 3. Ratio/Discrete 4. Nominal/Discrete

1. Honesty is a hypothetical construct rather than a concrete variable because it is: 2. Describe how honesty might be measured and defined using an operational definition. Check all that apply

1. An internal attribute or characteristic that cannot be observed directly 2. -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.

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. 1. Identify the population in this study. 2. Identify the sample in this study. 3. The average number that the researcher calculated is an example of a

1. The entire set of high school students in the United States. 2. The 100 students who were measured in the study. 3. statistic

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. 1. Identify the independent and dependent variables for this study. 2. What scale of measurement is used for the independent variable?

1. The independent variable is whether the motivational signs were posted, and the dependent variable is the amount of use of the stairs. 2. Nominal

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). 1. Is this an example of an experimental study or of a nonexperimental study? 2. Which of the following statements would explain how individual differences could provide an alternative explanation for the difference in weight between the groups? 3. Which of the research studies described below would be able to differentiate among those interpretations of the results? Check all that apply.

1. This is not an experiment because no independent variable is manipulated. The researchers are comparing two preexisting groups of individuals. 2. It is possible that participants in the reduced milkfat (skim or 1% milk) group also tended to be more sedentary than the participants in the other (whole or 2% milk) group.. 3. -A researcher could assign participants to two groups that receive different amounts of milkfat, matching the two groups in the amount of physical activity. -A researcher could randomly assign participants to groups that receive different amounts of milkfat. -A researcher could assign participants to two groups that receive different amounts of milkfat, holding constant characteristics like the amount of physical activity by participants in each.

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. 1. Is this an experimental study or a nonexperimental study? 2. Which of the following explanations for your answer is correct?

1. This is not an experiment. 2. The researchers are not manipulating an independent variable, but comparing preexisting groups of students who experience more or less video game violence.

Describe how the goal of an experimental research study is different from the goal for nonexperimental or correlational research. Identify the two elements that are necessary for an experiment to achieve its goal. 1. The goal of an experimental research study is which of the following? 2. To accomplish the goal, an experiment must do which of the following? Check all that apply.

1. To demonstrate the existence of a cause-and-effect relationship between two variables 2. -Control extraneous variables -Manipulate an independent variable

Statistical methods are classified into two major categories: descriptive and inferential. Describe the general purpose for the statistical methods in each category. 1. Descriptive statistics are generally used for which of the following? Check all that apply. 2. Inferential statistics are generally used for which of the following? Check all that apply.

1. To simplify and summarize data 2. To make general conclusions about populations using sample data