A survey was conducted to determine the state of the physical and psychological health of high school students.

Some of the survey questions related to student stress levels and student absences due to illness. The data on these variables are displayed in the image.

Which of the following conclusions are appropriate to draw based on the figure above? (Choose all that apply.)

• stress leads to illness

• as stress levels increase, the number of absences tends to increase.

• many student absences are due to stress.

• there is an indirect relationship between stress and illness.

• there is a positive correlation between stress level and number of absences.

Where does the independent variable go on a graph?

• Horizontal axis

• Vertical Axis

• Line of best fit

• We don't graph it

Researchers conducted a study in which 10 participants went to a laboratory around dinner time. The researcher assigned students to one of two groups by flipping a coin. Half of the participants were assigned to a “large bowl” group, and half were assigned to a “small bowl” group. By luck of the draw, 4 men and 1 woman were in the “large bowl” group, and 4 women and 1 man were in the “small bowl” group. Participants were told they could take as much pasta as they wanted from a serving bowl in the middle of the table, which was kept at a nearly full level. Participants were encouraged to go back for as many helpings of pasta as they wanted. In order to determine how much food each participant actually ate, the researchers measured the weight of the food that each participant took, as well as the amount that the participants left in their bowls.

The amount of pasta (in grams) each participant ate is shown in the table. The difference between the average pasta taken by the large bowl and small bowl participants was statistically significant. Which of the following does that mean?

• There was a noticeable difference between the average pasta taken in the large bowl and small bowl groups.

• The difference between the amount of pasta taken in each group was very likely caused by the bowl size.

• The study is reliable. If you were to do it again, you would get the same results.

• There is less than a 5% chance that the difference in the groups' average was due to random chance.

A study was conducted to investigate the role of framing on concern for healthy eating. Each participant (N = 100) was randomly assigned to one of two conditions. In the first condition, the participants read an article indicating that obesity is a disease. Participants in the second condition read an article indicating that obesity is the result of personal behaviors and decisions.

Participants were then asked to indicate how important it would be for them to eat a healthy diet. Scores ranged from 1 (not very important) to 9 (very important). The results are presented in the table.

What is the most appropriate conclusion the researchers can draw about the relationship between the variables in the study?

Dr. Nguyen is studying the emotional effects of watching television (TV) news. After taking a pretest measuring mood, each of the 200 college students in her sample is randomly assigned to watch fifteen minutes of either good news on TV, bad news on TV, a funny TV show, or no TV

at all. Her participants then complete an identical posttest measure of mood that they completed at pretest. Results of her research appear in the graph. Consider all of the differences between bar heights to be significant.

Which of the following would be accurate conclusions from her research?

• Watching TV caused the tested college students' moods to change.

• Watching good news on TV causes the tested college students' mood to increase.

• If parents show their children a funny show before bed, it will cause the childrens moods to decrease.

• Watching a funny show caused the tested college students' moods to decrease.

1. A group of researchers compared the effectiveness of massed versus distributed practice in preparing for a memory test. Each of two groups memorized the definitions of 40 vocabulary words.

In group A, there were 30 participants who were all under twenty-five years of age. Participants in group A used the method of distributed practice, studying for 30 minutes on each of four evenings. They were tested on the fifth morning at 7:00 A.M. In group B, there were 30 participants who were all over sixty years of age. Participants in group B used the method of massed practice, studying only from 6:30 P.M. to 8:30 P.M. on the evening before the test. They were tested the next morning at 7:00 A.M.

All participants completed a recall test. The test measured how quickly participants recalled the definitions. The results showed that the mean difference between the distributed practice group and the massed practice group was statistically significant. The researcher provided a list of the names and test scores for each individual participant in a letter to all participants.

In a well designed study, what does it mean to say there is a statistically significant difference between groups?

• There is less than a 5% chance that the results on the recall test were just due to chance.

• Less than 5% of the results on the recall test are due to chance.

• There is a less than 5% chance that the difference in recall test scores between groups was just due to chance.

• The correlation coefficient between groups was less than .05

• The difference between the groups' recall test scores was not likely due to chance.

A psychologist conducted a study at her home during an annual activity of children wearing masks and going door-to-door receiving candy. Some of the children arrived alone, while others arrived in a group. Over the course of the night, the psychologist asked half of the children to remove their masks when they arrived at her door based on whether a coin turned up heads (remove mask) or tails (keep mask) that was flipped as each child arrived. The remaining half kept their masks on. The psychologist told every child to take only one piece of candy. She then went inside the house, leaving the bowl of candy outside. This gave children the opportunity to take additional candy. The psychologist measured the percentage of children who took additional candy. The psychologist's hypotheses were that children would take more candy when they were alone and that children would take more candy when they were masked. The results are shown in the graph; assume all differences are significant.

What was the dependent variable in the study?

• whether or not the children were alone

• whether or not the children removed their masks

• whether or not the children took additional candy

• the number of children in the group

A psychologist conducted a study at her home during an annual activity of children wearing masks and going door-to-door receiving candy. Some of the children arrived alone, while others arrived in a group. Over the course of the night, the psychologist asked half of the children to remove their masks when they arrived at her door based on whether a coin turned up heads (remove mask) or tails (keep mask) that was flipped as each child arrived. The remaining half kept their masks on. The psychologist told every child to take only one piece of candy. She then went inside the house, leaving the bowl of candy outside. This gave children the opportunity to take additional candy. The psychologist measured the percentage of children who took additional candy. The psychologist's hypotheses were that children would take more candy when they were alone and that children would take more candy when they were masked. The results are shown in the graph; assume all differences are significant.

Explain why the psychologist cannot generalize her findings to all children.

A psychologist conducted a study at her home during an annual activity of children wearing masks and going door-to-door receiving candy. Some of the children arrived alone, while others arrived in a group. Over the course of the night, the psychologist asked half of the children to remove their masks when they arrived at her door based on whether a coin turned up heads (remove mask) or tails (keep mask) that was flipped as each child arrived. The remaining half kept their masks on. The psychologist told every child to take only one piece of candy. She then went inside the house, leaving the bowl of candy outside. This gave children the opportunity to take additional candy. The psychologist measured the percentage of children who took additional candy. The psychologist's hypotheses were that children would take more candy when they were alone and that children would take more candy when they were masked. The results are shown in the graph; assume all differences are significant.

Which of the following conclusions could the psychologist accurately draw from her data?

• Being in a group of children makes children more likely to take additional candy.

• Wearing a mask makes children more likely to take additional candy

• Children who arrived in groups were more likely to take additional candy than children who arrived alone.

• Deindividuation from being in a group and wearing a mask caused children to do things they might not have otherwise done

• Children who arrived in groups were more likely to keep their masks on than children who arrived alone.

A psychologist conducted a study at her home during an annual activity of children wearing masks and going door-to-door receiving candy. Some of the children arrived alone, while others arrived in a group. Over the course of the night, the psychologist asked half of the children to remove their masks when they arrived at her door based on whether a coin turned up heads (remove mask) or tails (keep mask) that was flipped as each child arrived. The remaining half kept their masks on. The psychologist told every child to take only one piece of candy. She then went inside the house, leaving the bowl of candy outside. This gave children the opportunity to take additional candy. The psychologist measured the percentage of children who took additional candy. The psychologist's hypotheses were that children would take more candy when they were alone and that children would take more candy when they were masked. The results are shown in the graph; assume all differences are significant.

Which of the psychologists hypotheses do the data support?

• children would take more candy when they were alone

• children would take more candy when they were masked