Question 1

The main advantage of an experimental study,in contrast to a correlational study,is that an experiment is

Accepted Answer

The main advantage of an experimental study is that it is more likely to demonstrate cause-and-effect. This is because in an experiment, the researcher manipulates the independent variable (the presumed cause) and observes its effect on the dependent variable (the presumed effect), while controlling for other variables. In contrast, in a correlational study, the researcher simply observes the relationship between variables without manipulating them, making it impossible to establish causation with certainty.

Question 2

The main difference between a correlational study and an experiment is that in a correlational study

Accepted Answer

In a correlational study, the investigator does not control either variable, whereas in an experiment, the experimenter manipulates the independent variable and controls for extraneous variables. Therefore, individuals are not randomly assigned to groups in a correlational study, and there is both an independent and dependent variable present (which the investigator does not manipulate or control). Additionally, while the experimenter begins with a hypothesis in both types of studies, this is not the main difference between them.

Question 3

Juanita has a headache one evening so she takes the experimental drug Zenax to eliminate her headache.She goes to sleep and finds her headache gone the next day.Do these results show that Zenax was effective?

Accepted Answer

The disappearance of Juanita's headache could be attributed to other factors such as natural recovery or the placebo effect, rather than the efficacy of Zenax itself.

Question 4

An experimenter exposed students to one hour of soft,intermediate,or loud noise and then tested their ability to solve puzzles.What was the independent variable in this experiment?

Accepted Answer

The independent variable in this experiment is the loudness of the noise, as this is the variable that is manipulated or controlled by the experimenter to observe its effects on the dependent variable (ability to solve puzzles). The other options (B, C, and D) are not the independent variable in this experiment.

Question 5

Dr.Rodentz deprives several rats of food for different lengths of time and then places them at the start of a maze.He records how long each rat takes to reach the food at the end of the maze.The time needed to reach the food is the

Accepted Answer

The time taken by each rat to reach the food is the dependent variable because it depends on the level of food deprivation. The independent variable is the length of time the rats are deprived of food. The normal distribution and inferential statistics are not relevant to the design of the experiment but might be used in the analysis of the data.

Question 6

An experimenter kept students in a hot,neutral,or cold room and then tested their ability to memorize poetry.What was the dependent variable in this experiment?

Accepted Answer

The dependent variable is the variable that is being measured or tested in the experiment. In this case, it is the ability of the students to memorize poetry, which is measured through their success in doing so. Therefore, D is the correct answer. A, B, and C are independent variables, as they are variables that are being manipulated or controlled by the experimenter.

Question 7

The main difference between a correlational study and an experiment is that in an experiment,

Accepted Answer

In an experiment, the investigator intentionally manipulates the independent variable to observe the effect on the dependent variable, while in a correlational study, the variables are not intentionally manipulated. Option A is incorrect because participants may or may not be aware of the hypothesis being tested in both types of studies. Option B is incorrect because in a correlational study, individuals may naturally receive different levels of the variable being studied. Option C is incorrect because experiments involve manipulation of variables, which would interfere with the participants' normal life.

Question 8

An instructor gives weekly tests in one class and just one midterm exam to a second class and then compares performances of students in the two classes when they all take the same final exam.What is the dependent variable in this experiment?

Accepted Answer

The dependent variable in this experiment is the students' scores on the final exam, as this is what is being compared between the two classes. The number of students in each class, the difficulty of the final exam, and the number of tests given before the final exam are all independent variables that may affect the students' scores, but they are not the focus of the experiment.

Question 9

One group of students who spent the weekend studying for the test got better scores than a group who spent the weekend camping.That statement could be the result of an experiment or a correlational study.To decide whether it was an experiment,we would have to know the answer to the following question:

Accepted Answer

Knowing whether the students were assigned to the study or camping groups or if they chose their activity themselves would help us determine whether the study is an experiment or a correlational study. If the groups were randomly assigned, then it would be an experiment as the researcher manipulated the variable (study vs. camping) and observed its effect on the dependent variable (test scores). However, if the students chose their own activity, it would be a correlational study, as the researcher only observed the relationship between the two variables without manipulating them.

Question 10

Professor Taylor provides a review session for half the students taking Psychology 101.Later he compares their scores against those of the other students.What is the independent variable in this experiment?

Accepted Answer

The independent variable is the variable that is manipulated or changed by the experimenter. In this case, the review session is the independent variable because Professor Taylor is providing it only to half of the students, while the other half does not receive this intervention. The test scores are the dependent variable because they are being measured as an outcome of the review session. The total number of students and the difficulty of the test are not independent variables in this experiment because they are not being manipulated by the experimenter.

Question 11

An independent variable is one that

Accepted Answer

An independent variable is the variable that the experimenter changes or controls in order to measure the effect on the dependent variable. Therefore, only choice C is correct. Choice A is incorrect because an irrelevant variable would not be considered an independent variable in the experiment. Choice B is incorrect because the experimenter must be able to control or measure the independent variable in order to conduct a valid experiment. Choice D is incorrect because measuring the independent variable after the treatment would not make sense - the independent variable is the one that is manipulated, not measured.

Question 12

An experimenter had people exercise much,a little,or not at all and then measured how much they ate at dinner 2 hours later.What was the independent variable in this experiment?

Accepted Answer

The independent variable in this experiment is the amount of exercise, as it is the variable that the experimenter is manipulating and controlling in order to measure its effect on how much people eat at dinner.

Question 13

An experimenter kept students in a hot,neutral,or cold room and then tested their ability to memorize poetry.What was the independent variable in this experiment?

Accepted Answer

The independent variable in this experiment is the temperature of the room. This is the variable that is being manipulated by the experimenter in order to see if it has an effect on the students' ability to memorize poetry.

Question 14

Studies find that people who exercise regularly tend to have a more cheerful outlook on life.What conclusion,if any,can we draw from these data?

Accepted Answer

The data only show a correlation between exercise and a cheerful outlook, not causation. It does not specify whether exercise improves mood, cheerfulness increases activity, or if it's due to another factor like age or health.

Question 15

An experimenter had participants exercise much,a little,or not at all and then measured how much they ate at dinner two hours later.What was the dependent variable in this experiment?

Accepted Answer

The dependent variable in this experiment is the amount of food eaten at dinner two hours later. This is the variable that is being measured and is affected by the independent variable, which is the amount of exercise.

Question 16

A dependent variable is a variable that

Accepted Answer

The dependent variable is the variable that is being measured by the experimenter to determine how it was affected by the independent variable. It is the outcome variable in the experiment and is often affected by the manipulation of the independent variable.

Question 17

After using which of the following methods would an experimenter be most confident in making statements about cause and effect?

Accepted Answer

A true experiment involves manipulating an independent variable and observing its effects on a dependent variable, while controlling for extraneous variables. This allows for the establishment of cause-and-effect relationships, making it the most reliable method for making statements about cause and effect.

Question 18

A psychologist evaluates 60 people at the start of therapy and again at the end of 8 weeks of therapy.She reports that 55 of the 60 are "improved," and concludes that the therapy was effective.One flaw in this study is that it lacks

Accepted Answer

The study lacks a control group. Without a control group, it is impossible to determine if the improvements observed in the participants were actually due to the therapy, or if they were simply a result of natural recovery or other factors. A control group is essential for establishing the effectiveness of any intervention.

Question 19

The advantage of the experimental method as opposed to correlational studies is that an experiment

Accepted Answer

The experimental method allows researchers to manipulate variables and control extraneous variables, which allows for the discovery of cause-and-effect relationships. Correlational studies, on the other hand, only allow for the identification of relationships between variables but cannot establish causation.

Question 20

Professor Taylor provides a review session for half the students taking Psychology 101.Later he compares their test scores against those of the other students.What is the dependent variable in this experiment?

Accepted Answer

The dependent variable is the variable that is being measured or observed in order to determine the effect of the independent variable. In this case, the independent variable is the review session provided by Professor Taylor, and the dependent variable is the test scores of the students. By comparing the test scores of the students who attended the review session to those who did not, Professor Taylor is determining the effect that the review session had on their test performance.

Quiz 2: Scientific Methods in Psychology