Question

Eight studies are described briefly below. What research method was employed in these studies, also write the rationale of your choice of response.
1.   A researcher is interested in whether drinking water right before bed increases the likelihood that children will wet the bed at night. The researcher recruits 50 5-year-old children to participate in her study. Twenty-five children are given two glasses of water two hours before their bedtime (one glass per hour) and twenty-five children are prohibited from receiving liquids within two hours of their bedtime.
2.   A researcher was interested in how children learn how to settle disagreements with peers. The researcher talked to his five-year-old daughter and asked her to describe how she interacted with her peers. The researcher then read a few stories to his daughter about children her age who got into disagreements and asked her what she would do in that situation. The researcher continued to interview his daughter like this for five years.
3.   University officials have noticed that there is a relationship between scores on the Graduate Record Exm (GRE) and performance in graduate school. Specifically, those students with the highest scores tend to do best in school.
4.   In an attempt to determine which method would assure the best class attendance, an educational psychologist had one teacher reward students for attending class with extra points, a second teacher punish absences by deducting points, a third teacher scold students for absences, and a fourth teacher do nothing unusual. Attendance was best in the first class where the teacher rewarded the students.
5.   A researchers is interested in whether people are more likely or less likely to help someone in distress when others are present. Some subjects were testes when they alone were witness to someone in distress, while others were tested when many people were present. The researcher discovered that witnesses were much more likely to help when hey alone witnessed the person in distress.
6.   In an attempt to determine which method would assure the best class attendance, an educational psychologist had one teacher reward students for attending class with extra points, a second teacher punish absences by deducting points, a third teacher scold students for absences, and a fourth teacher do nothing unusual. Attendance was best in the first class where the teacher rewarded the students.
7.   A researcher who was suspicious that hyperactivity in children was related to the amount of sugar in their diet recorded both sugar intake and activity level for a sample of children over a five month period. The results indicated that those children who had consumed the most sure tended to be the most active.
8.   In an investigation of drug abuse, it was noted that there was a relationship between the ages at which an individual first started experimenting with drugs and the severity of the drug abuse problem. Specially, those who experimented with drugs at the earliest age tended to be those with the most severe drug abuse problems.
9.   To investigate the relationship between anxiety and test performance, three groups of subjects are tested under one of the following conditions: high anxiety, moderate anxiety, low anxiety. The moderate anxiety group performs between on the test than either the high anxiety or the low anxiety groups.
10.   Researchers looking at the relationship between intelligence and birth order found that the children with the highest IQ scores were most likely to the first born in the family.
11.   In a study of animal motivation, researchers varied the number of hours their laboratory animals were deprived of food. While some had food continuously available, others were deprived for 12 hours, and some were deprived for 24 hours. The researchers discovered that the animals deprived for 24 hours worked harder for food than did the others.

Answer 1

1. It is an experimental method. This is because it involves studying a causal relationship where the independent variable is being manipulated (water). Random assignment is also involved.

2. This is a longitudinal survey. This is because information is being collected from the same person over several years.

3. It is a correlational design. This is because a relationship between two variable needs to be investigated. However, the relationship is not necessarily causal. Moreover, the independent variable cannot be manipulated here.

4. This is a quasi experimental study. While the manipulation of independent variable was present, there was no random assignment. Already existing classes were used due to practicality.

5. This will utilize a between subjects experimental design. Here, the independent variable was manipulated across conditions. Different subjects were used for different conditions.

6. This is a quasi experimental study. While the manipulation of independent variable was present, there was no random assignment. Already existing classes were used due to practicality. The children cannot be randomly assigned to conditions by shuffling the classes.

7. This is a correlational design. A relationship between sugar consumption and activity level was established. However, the relationship was not causal in nature. Moreover, already existing conditions were measured rather than manipulating a variable.

8. This is a correlational design. The researcher investigated a relationship between the age and the severity of drug use. No experimental manipulation is involved here.

9. This is an experimental design. It involved the use of three different conditions for different levels of the independent variable. A cause and effect relationship was established.

10. This is a correlational design. Data on already existing conditions was collected to establish the direction of relationship between two variables.

11. This is an experimental design as it involves the manipulation of independent variable across conditions.