1 Section 3-2 Reader’s Guide (cont.) Click the Speaker button to listen to Exploring Psychology. Click the mouse button or press the Space Bar to display the information. Section 3 begins on page 47 of your textbook. Vocabulary –descriptive statistics  –frequency distribution  –normal curve  –central tendency  –variance  –standard deviation  –correlation coefficient  –inferential statistics –statistics 

2 Section 3-4 Click the mouse button or press the Space Bar to display the information. How many times have you been told that in order to get good grades, you have to study?  A psychology student named Kate has always restricted the amount of TV she watches during the week, particularly before a test.  She has a friend, though, who does not watch TV before a test but who still does not get good grades.  This fact challenges Kate’s belief. Introduction (cont.)

3 Section 3-5 Click the mouse button or press the Space Bar to display the information. Although Kate hypothesizes that among her classmates, those who watch less TV get better grades, she decides to conduct a survey to test the accuracy of her hypothesis.  Kate asks 15 students in her class to write down how many hours of TV they watched the night before a psychology quiz and how many hours they watched on the night after the quiz. Introduction (cont.)

4 Section 3-6 Click the mouse button or press the Space Bar to display the information. Kate collects additional data.  She has her participants check off familiar products on a list of 20 brand-name items that were advertised on TV the night before the quiz.  Kate also asks her participants to give their height.  When the data are turned in, Kate finds herself overwhelmed with the amount of information she has collected. Introduction (cont.)

5 Section 3-7 Click the mouse button or press the Space Bar to display the information. How can she organize it all so that it makes sense?  statistics the branch of mathematics concerned with summarizing and making meaningful inferences from collections of data How can she analyze it to see whether it supports or contradicts her hypothesis?  Introduction (cont.) The answers to these questions are found in statistics, a branch of mathematics that enables researchers to organize and evaluate the data they collect.

6 Section 3-8 Click the mouse button or press the Space Bar to display the information. descriptive statistics the listing and summarizing of data in a practical, efficient way Descriptive statistics is the listing and summarizing of data in a practical, efficient way, such as through graphs and averages. Descriptive Statistics

7 Section 3-9 Click the mouse button or press the Space Bar to display the information. One of the first steps that researchers take to organize their data is to create frequency tables and graphs.  Tables and graphs provide a rough picture of the data.  Are the scores bunched up or spread out? What score occurs most often?  Distributions of Data

8 Section 3-10 Click the mouse button or press the Space Bar to display the information. Kate is interested in how many hours of TV her participants watched the night before and the night after the quiz.  She uses the numbers of hours of TV viewing as categories, and then she counts how many participants reported each category of hours before and after the quiz.  Kate has created a table called a frequency distribution. Distributions of Data (cont.)

9 Section 3-11 Click the mouse button or press the Space Bar to display the information. A frequency distribution is a way of arranging data so that we know how often a particular score or observation occurs.  frequency distribution an arrangement of data that indicates how often a particular score or observation occurs With her information, Kate could figure out percentages. Distributions of Data (cont.)

10 Section 3-13 Click the mouse button or press the Space Bar to display the information. Imagine that Kate could measure how much TV everyone in Chicago watched one night.  A few people would watch little or no TV, a few would have the TV on all day, while most would watch a moderate amount of TV.  Therefore, the graph would be highest in the middle and taper off toward the tails, or ends, of the distribution, giving it the shape of a bell. Distributions of Data (cont.)

11 Figure 3-1 Distributions of Data

12 Section 3-14 Click the mouse button or press the Space Bar to display the information. This curve is called the normal curve (or bell-shaped curve).  normal curve a graph of frequency distribution shaped like a symmetrical, bell-shaped curve; a graph of normal distribution Many variables, such as height, weight, and IQ, fall into such a curve if enough people are measured.  The normal curve is symmetrical. Distributions of Data (cont.)

13 Section 3-16 Click the mouse button or press the Space Bar to display the information. The mode is the most frequent score; in a graphed frequency distribution, the mode is the peak of the graph.  When scores are put in order from least to most, the median is the middle score; since the median is the midpoint of a set of values, it divides the frequency distribution into two halves.  The mean is what most people think of as an “average” and is the most commonly used measure of central tendency. Measures of Central Tendency (cont.)

14 Chart 3-1 A Frequency Polygon

15 Section 3-18 Click the mouse button or press the Space Bar to display the information. The range uses only a small amount of information, and it is used only as a crude measure of variance.  standard deviation a measure of variability that describes an average distance of every score from the mean The standard deviation is a better measure of variance because, like the mean, it uses all the data points in its calculation. Measures of Variance (cont.)

16 Chart 3-2 Standard Deviation

17 Section 3-19 Click the mouse button or press the Space Bar to display the information. A correlation coefficient describes the direction and strength of the relationship between two sets of observations.  correlation coefficient describes the direction and strength of the relationship between two sets of variables Coefficients can have positive and negative correlations.  A scatterplot is a graph of participants’ scores on the two variables. Correlation Coefficients

18 Section 3-20 Click the mouse button or press the Space Bar to display the information. Psychologists also want to make generalizations about the population from which the participants come.  inferential statistics numerical methods used to determine whether research data support a hypothesis or whether results were due to chance Using inferential statistics, researchers can determine whether the data they collect support their hypotheses, or whether their results are merely due to chance outcomes. Inferential Statistics

19 Chart 3-3 A Scatterplot

20 Section 3-21 Click the mouse button or press the Space Bar to display the information. The researcher must determine whether the findings from the experiment support the hypothesis or whether the results are due to chance.  To do this, the researcher must perform a variety of statistical tests, called measures of statistical significance. Probability and Chance

21 Section 3-23 Click the mouse button or press the Space Bar to display the information. When the probability of a result is whatever level the researcher sets, we say that the result is statistically significant.  It is important to remember that probability tells us how likely it is that an event or outcome is due to chance, but not whether the event is actually due to chance. Statistical Significance (cont.)

22 Chapter Assessment 6 Recalling Facts How does a self-fulfilling prophecy present a problem for researchers? Click the mouse button or press the Space Bar to display the answer. Participants or experimenters may have expectations about the research or experiment that can influence or bias the results.

Psychology Journal (Section 3) Gather the height and shoe size from every member of your family. Graph the information in your journals. Consider if any useful insights can be made from this data.

Chapter Concepts 1 Continued on next slide.

Chapter Concepts 2

Daily Focus 1.1 Continued on next slide.

Daily Focus 1.2 Click the mouse button or press the Space Bar to display the answers. Answers: 1.naturalistic observation  2.case study  3.surveys

Daily Focus 2.1 Continued on next slide.

Daily Focus 2.2 Click the mouse button or press the Space Bar to display the answers. Answers: 1.the labels on the cans  2.changes in facial expressions or body language or words used  3.Researcher cannot identify the products, so it is less likely that bias will be introduced.

Daily Focus 3.1 Continued on next slide.

Daily Focus 3.2 Click the mouse button or press the Space Bar to display the answers. Answers: 1.$30,000  2.The median is the center point–the number of employees paid more than the median equals the number of employees paid less.  3. $55,  4.total income divided by total employees  5. mean income

Survey From the Classroom of James Matiya Carl Sandburg High School, Orland Park, IL Chapter Activity 1 In this activity, you are asked to conduct a survey. You should ask four people of different age groups to read the paragraph on the following slide and declare whether the substance should be banned or not. After conducting the survey, you should combine your answers with your classmates. Tally your answers and then calculate mean, mode, and median. Separate and tally the answers between males and females, different age groups, and different class levels. Discuss the results as a class. Continued on next slide.

Chapter Activity 2 Ban Dihydrogen Monoxide! This substance has been found in many different forms. It may be found in solid states, gaseous states, and frozen states. In the solid state, people have been known to lose their lives to falling parts of it. In the frozen state, it is responsible for the death and injury of millions of people. It has destroyed millions of miles of roads as well. In the gaseous state, people have been burned, have difficulty breathing, and it has made people extremely warm even to the point of becoming physically sick. Government agencies monitor the levels of this substance. The substance has been used as an industrial coolant, especially in nuclear power plants. It has been found along the highways in different sizes of containers, despite the fact that it may cause erosion to the soil and will weaken the effectiveness of cars’ brakes. Would you support a ban of this substance? Survey From the Classroom of James Matiya Carl Sandburg High School, Orland Park, IL

FYI 1.1 In 1967, Neal Miller and Leo DiCara stunned the psychological and medical world by reporting that they had trained rats to control their heart rates. All attempts to replicate Miller and DiCara’s study failed, however– including their own. What went wrong? To date, nobody has found an answer.

Cultural Connections 3.1 Milgram’s experiment was conducted in Germany and Japan. Both cultures rate high in measures of respect for and compliance with authority. The German and Japanese participants showed an even higher rate of obedience–more than 80 percent for both groups.