Question 1

Professor Izadi is interested in the association between sleep and cognitive performance.He surveyed his students about the number of hours they slept the night before the exam and then correlated these scores with their test grades.He found a +.81 correlation between these two variables.What does this result mean?

Accepted Answer

A correlation coefficient ranges from -1 to +1, with +1 indicating a perfect positive correlation and -1 indicating a perfect negative correlation. In this case, a correlation coefficient of +.81 indicates a strong positive correlation between sleeping the night before an exam and test grades. Thus, choice C is the correct answer.

Question 2

When conducting an experiment on time management, Jamie assigns everyone who arrives before noon to the experimental group and everyone who arrives after noon to the control group.In the context of experimental research methods, what is wrong with Jamie's experiment?

Accepted Answer

Jamie's experiment lacks true random assignment, as the grouping is based on arrival time rather than a random selection process. This can lead to bias and affect the validity of the experiment.

Question 3

A correlation coefficient indicates the

Accepted Answer

A correlation coefficient measures the strength and direction of the association between two variables. It does not establish causation or address biases in the study.

Question 4

What does the magnitude of a correlation coefficient indicate about the variables in a correlational study?

Accepted Answer

The magnitude of a correlation coefficient indicates the strength of the relationship between the variables in a correlational study. A larger magnitude means there is a stronger relationship between the variables, while a smaller magnitude indicates a weaker relationship. The size of the variables, number of data points, and direction of the relationship are all independent of the magnitude of the correlation coefficient.

Question 5

In the context of psychological research methods, which of the following refers to a carefully regulated procedure in which the researcher manipulates one or more variables that are believed to influence some other variable?

Accepted Answer

Experiments involve manipulating variables to determine their effect on another variable.

Question 6

A researcher is conducting an experiment to test the effects of violent video-game-play on aggression.Which of the following could be the dependent variable in this example?

Accepted Answer

The dependent variable in this experiment would be the scores on an aggressive behavior survey since it is the variable being measured in relation to the independent variable of violent video-game-play. The other options listed are either independent variables or extraneous variables that are not being measured or manipulated in the experiment.

Question 7

Dr.Steinguard wants to demonstrate a cause-and-effect relationship between stress and memory.Which of the following research methods should he use?

Accepted Answer

Dr. Steinguard should use the experimental method to demonstrate a cause-and-effect relationship between stress and memory. This method involves manipulating the independent variable (in this case, stress) to see its effect on the dependent variable (memory), while controlling for extraneous variables. This will allow for conclusions about the causal relationship between stress and memory to be drawn.

Question 8

Which of the following is a potential problem of using correlational studies in psychological research?

Accepted Answer

Correlational studies cannot establish a cause-and-effect relationship between variables. This is because correlation only shows how two variables are related to each other, but it does not explain why they are related or which variable causes the other. Therefore, other research methods, such as experiments, are needed to determine causality in psychological research.

Question 9

_____ provide ways by which correlational researchers may attempt to demonstrate causal relations among variables, even though the causal relationship may still be somewhat unclear.

Accepted Answer

Longitudinal designs can help establish causality by measuring the same variables in the same subjects over time, allowing researchers to establish a temporal order of events and rule out alternative explanations for the observed relationship between variables. Random selection techniques, sampling designs, and survey designs do not directly address the issue of causality.

Question 10

In correlations research, third variables are also called

Accepted Answer

Third variables are also called confounds because they can create a spurious relationship between two variables of interest, making it difficult to determine true cause and effect. Confounds are variables that are not measured but can affect the relationship between the variables being studied.

Question 11

In the context of experimental research, the logic of random assignment is

Accepted Answer

Random assignment ensures that the potential differences between the groups on other characteristics, such as age, gender, and personality traits, will be distributed equally across the groups, which reduces the likelihood of confounding variables influencing the results. Stratification may lead to unequal representation of variables among the groups, which can result in biased outcomes. Therefore, random assignment is the most effective way to control for extraneous variables in experimental research.

Question 12

_____ refers to researchers' allocation of participants to groups by chance, to reduce the likelihood that an experiment's results will be due to preexisting differences between groups.

Accepted Answer

Random assignment refers to researchers assigning participants to different groups by chance, which helps to reduce the possibility that preexisting differences between groups could affect the study's results. Selection bias occurs when the researchers do not assign participants randomly or select only certain types of participants, which can lead to biased results. Experimenter bias occurs when the researchers unconsciously or consciously influence the study's results, which can also affect the validity of the results. Random selection refers to the process of selecting participants from a larger population in a random manner, which can help to ensure that the study's sample is representative of the population.

Question 13

Aaron wants to study the association between sleep deprivation and the number of hours spent on a computer every day.He is not keen to establish causation, but would like to determine whether and how the increase or decrease in one variable is related to the increase or decrease in the other variable.Which of the following research methods is likely to be most effective for Aaron's study?

Accepted Answer

Correlational research is the most effective research method for Aaron's study because it examines the relationship between two variables without manipulating them. This will allow Aaron to determine if there is a relationship between sleep deprivation and hours spent on a computer, without making any assumptions about causation. Surveys and case studies may also provide useful information, but correlational research is specifically designed for this purpose. Experimental research, on the other hand, would require manipulating one variable and measuring the effect on the other, which is not necessary for Aaron's research question.

Question 14

Professor Jordan has suggested to his students that as study time increases, grades increase.The professor is describing a

Accepted Answer

The professor is describing a positive correlation between study time and grades, meaning as one variable increases, so does the other.

Question 15

Pretend that you want to determine the relationship between caffeine intake and performance on a midterm exam.As students sit down to take the exam, you ask them to write the number of cups of tea, soda, or coffee they ingested two hours prior to the exam.You also obtain their exam scores.You calculate the correlation coefficient between the two variables to be +0.82.What can you conclude?

Accepted Answer

The correlation coefficient of +0.82 indicates a strong positive relationship between caffeine intake and exam performance. This means that as caffeine intake increases, so does exam performance. However, correlation does not equal causation and other variables could also be at play. Therefore, we cannot conclude that caffeine consumption is the sole factor for higher exam scores.

Question 16

In experimental research, the _____ is a manipulated experimental factor and _____ is the outcome.

Accepted Answer

The independent variable is the factor that is manipulated by the researcher, and the dependent variable is the outcome measure that is affected by the independent variable. Option A is incorrect because it reverses the roles of the independent and dependent variables. Option C is not correct because a confounding variable is an extraneous variable that affects the relationship between the independent and dependent variable. Option D is not correct because a confounding variable is not a variable that is manipulated by the researcher.

Question 17

Professor Wong measured the intelligence and temperament of a group of preschoolers.He plans to follow the same group of participants over time and collect similar data when the children are in 3 grade, 6 grade, and 9 grade.This is an example of which type of research design?

Accepted Answer

This is a longitudinal design because it involves following the same participants over an extended period of time and collecting data at multiple points.

Question 18

Which of the following research methods allow(s) researchers to determine causality?

Accepted Answer

Experimental studies allow researchers to manipulate an independent variable and observe its effect on a dependent variable, thus allowing for the determination of causality. Surveys, observations, and case studies do not involve manipulation and therefore cannot establish causality.

Question 19

Longitudinal research involves

Accepted Answer

Longitudinal research involves observing and measuring the same variables periodically over time. This type of research is often used to study developmental changes and identify patterns of behavior or attitudes over extended periods. Random assignment (B) is typically used in experimental designs, while random selection (C) is a method of sampling to ensure that the participants are representative of the population. Uncovering unconscious motives and conflicts (D) is associated with psychoanalytic approaches to research and not typically a characteristic of longitudinal research.

Question 20

Dr.Simpson finds a positive .50 correlation between ice-cream-cone sales and violent crimes in a community.Which of the following represents the best interpretation of this result?

Accepted Answer

The correlation found between ice-cream-cone sales and violent crimes suggests that there is an association between these two variables. However, correlation does not equal causation. It is possible that a third variable, such as heat, may contribute to both higher ice-cream sales and more violent behavior. It is unlikely that ice cream consumption itself causes people to become more violent. Therefore, choice B is the best interpretation.

Quiz 1: The Science of Psychology