st095 ยป

st095 Problem Set 1


Classical Music

A researcher finds that students who listen to classical music in elementary school tend to have better grades in high school. There was no random assignment to conditions or manipulation of an independent variable. In other words, they didn't just look at a bunch of random students. We might not even know which students they looked at. But then the researcher recommends children will listen to classical music because that will cause them to perform better in school. What's wrong with this logic? So let's that's all that apply


This scatter plot here shows the relationship between the number of caffeinated drinks people consume and the hours that they sleep. Each of these dots represents one person. So for example, this person consumed about three caffeinated drinks and only slept about five hours. This data was collected from a survey of nine individuals. From this graph what can you conclude?

Video Games

A researcher found a relationship between the number of hours spent playing violent video games per week and the level of aggression shown by adolescent males. This is measured by the aggression scale, which is someones self reported measure of aggressive behavior. More hours spent playing correspond at a higher aggression score. Giving this information, what can we say is true?

English Teaching

At an elementary school, there are a lot of students for which Spanish is their first language. Now let's say there are two ways of teaching English to them. One way is to only teach them in English. Another way is to teach them in both English and Spanish. So researchers randomly assign students to one of these two groups. Once students were assigned to either being taught in English only or in both Spanish and English, it stayed that way. After a while, the researchers gave each student a reading comprehension test. On the day of testing for the English only group, the temperature was 72 degrees Fahrenheit, but for the bilingual group, the temperature was 100 degrees Fahrenheit, which is pretty hot. When the scores were calculated, the English only group had an average of 70%, while the bilingual group had an average of 55%.


This is an African pouched rat. They are particularly good at detecting TNT in land mines. They are trained using something called tea eggs which have TNT in them. TNT is an explosive found in many land mines. If the African pouched rats were able to find the tea egg. Eggs. They were given a food reward. But if they scratched near tea eggs that did not contain TNT, then they did not receive a food reward. Scratching near the tea eggs was considered the indicator response. The researchers found that the training was very successful in teaching the rats to detect real land mines in the field. This was measured by the number of meters of land cleared by explosives. And by the number of landmines that they found. Based on this study, what can we say is true?


Let's say we randomly assigned with insomnia to 1 of 2 treatment conditions. In 1 condition, participants received 20 milligrams of Ambien. And in the other condition, patients received a Placebo pill. The participants did not know which they received. After taking their pills. The participants slept in a sleep laboratory to help control for lurking variables.The next morning they rated their quality of sleep on a scale of 1 to sleep and 10 being excellent. They reported this skill to a phsycologist, who also did not know which treatment each person was assigned to. It turns out that the people in the Ambien group reported a higher quality of sleep with an average of reported an average of 5. What can we say is true about this scenario? Select all that apply.


For people with Coronary Heart Disease, some researchers compared three treatments for depression. One group took Zoloft. Another group engaged in aerobic exercise a Placebo pill. After 4 months, severity of depression was measured using the Hamilton grading scale for depression. The group that did aerobic exercise 3 times per week showed the largest decrease in depression scores, followed by Zoloft. And finally, those who took the placebo pill showed the smallest decrease in depression scores. Which of the following is true? Select all that apply.


Have you ever had the winter blues where you're just depressed during the winter? For some people, this is an actual recognized disorder called Seasonal Affective Disorder. This applies to any season. Throughout most of the year, people with SAD have normal mental health but experience depression during certain seasons, even Spring or Summer. Researchers tried to figure out how to treat SAD. 95 people were randomly assigned to 1 of 3 conditions. Bright light therapy, which is where participants were exposed to 10,000 lux for 30 minutes every morning. From 6 o'clock until 6:30 a.m. Lux is the international standard measurement of illuminants. The second group received Dawn Simulation, which was a dawn signal, in which people were exposed to lux that peaked at 250. And this lasted 1.5 hours. And the 3rd was a Placebo condition which was just 1.5 hours of a dim red light, at only 0.5 lux, this lasted from 4:30 am until 6 am. The number of people in each group was as follows, 33 in the bright light therapy. 31 in the dawn situation, and 31 in the placebo. After 6 weeks, all the subjects were blindly rated by a psychiatrist. So the psychiatrist did not know which treatment each person was exposed to. The psychiatrist used the Structured Interview Guide for the Hamilton Depression Rating for Seasonal Effective Disorder. This measures a person's level of this type of depression on a scale of 0 to 89, with higher numbers indicating greater severity of depression. The researchers found that Dawn simulation was associated with greater recovery. That is compared to the Placebo group and the Bright Light Therapy group.