exam 7 part 2

What is the main goal of probability sampling in research?

To ensure a representative sample

Larger sample sizes generally reduce sampling error. (True/False)

True

Briefly explain the difference between simple random sampling and stratified random sampling.

Simple random sampling gives every individual an equal chance of being selected. Stratified random sampling divides the population into subgroups and selects participants from each subgroup.

Which of the following is an example of descriptive research? a) Testing the effects of sleep deprivation

b) Observing study habits of college students

Informed consent is required in all studies involving human participants. (True/False)

true

What are two potential ethical concerns researchers must consider when designing a study?

Informed consent and confidentiality

A positive correlation means: a) As one variable increases, the other decreases b) The two variables are unrelated c) As one variable increases, the other also increases d) As one variable decreases, the other increases

c) As one variable increases, the other also increases

Correlational research can determine the cause of a relationship between two variables. (True/False)

False

Describe the difference between a positive and negative correlation.

A positive correlation means both variables increase together; a negative correlation means as one increases, the other decreases.

What is one key feature of an experiment? a) It always includes a large sample size b) It manipulates at least one independent variable c) It does not require a control group d) It always measures multiple dependent variables

b) It manipulates at least one independent variable

Random assignment is crucial for ensuring that groups are equivalent at the start of an experiment. (True/False)

True

What are the three essential ingredients of an experiment?

Manipulation of the independent variable, random assignment, control of extraneous variables

In a 2x3 factorial design, how many independent variables are there? a) 2 b) 3 c) 5 d) 6

a) 2

In a factorial design, interaction effects occur when the effect of one independent variable depends on the level of another independent variable. (True/False)

True

What is the difference between a main effect and an interaction effect?

A main effect is the effect of one independent variable on the dependent variable, while an interaction effect occurs when the effect of one independent variable depends on the level of another.

Which of the following is NOT a potential cost in the cost-benefit analysis conducted by an Institutional Review Board (IRB)? a) Time and effort required from participants b) Potential psychological harm to participants c) Improvement in future research techniques d) Violation of participants’ confidentiality

c) Improvement in future research techniques

Deception in research can never be justified, regardless of the study's potential benefits. (True/False)

False

List two conditions under which researchers can use deception in their studies.

If the study has significant scientific value and the deception does not harm the participants.

What is sampling error?

The difference between the characteristics of the sample and the characteristics of the population from which it was drawn​.

What is the main purpose of control groups in experimental research?

Control groups are used to compare results with the experimental group to see if the independent variable had an effect​.

What does external validity refer to in an experiment?

The extent to which the results of a study can be generalized to other populations, settings, or times​.

Define a within-subjects design in an experiment.

A design in which the same participants are exposed to all levels of the independent variable​.

What is internal validity?

The degree to which a researcher can confidently say that changes in the dependent variable were caused by the independent variable​.

What is pretest-posttest design?

A design where participants are tested on the dependent variable before and after the experimental manipulation​.

What does the term error bars represent in a graph?

Error bars represent confidence intervals, showing the range in which the true population mean is likely to fall​.

What is the coefficient of determination (r²)?

The proportion of variance in the dependent variable that is predictable from the independent variable​.

In correlational research, what does an r value of -1.00 indicate?

A perfect negative correlation, meaning as one variable increases, the other decreases in a perfectly linear manner​.

What are main effects in a factorial design?

The effect of one independent variable on the dependent variable, ignoring other independent variables​.

What are interaction effects in a factorial design?

The effect of one independent variable on the dependent variable depends on the level of another independent variable​.

What does counterbalancing help control in a within-subjects design?

Counterbalancing helps control for order effects like practice or fatigue effects​.

What is placebo effect in an experimental study?

A change in participants' behavior due to their belief that they are receiving a treatment, rather than the treatment itself​.

What is the difference between matched random assignment and simple random assignment?

In matched random assignment, participants are first grouped based on a variable, then randomly assigned to conditions, while simple random assignment involves purely random placement​.

Define systematic variance.

Variance in a dependent variable that is accounted for by the independent variable​.

What is minimal risk in ethical research?

The risk of harm that is no greater than what people ordinarily encounter in daily life​​.

What is a confederate in experimental research?

A person who is secretly working with the researcher and appears to be a participant or bystander​.

What is the main difference between probability and nonprobability samples?

a) In a probability sample, the researcher can determine the likelihood that a member of the population will be included in the sample, whereas that likelihood cannot be determined in a nonprobability sample

In which of the following instances might the error of estimation be lowest?

b) The sample is large

In order to form a simple random sample, you first need a list of all the members in the population. This list is called the:

b) Sampling frame

I am conducting a study on the effects of standardized testing (SOLs) on third graders in Virginia. I first randomly select 20 counties in the state, then randomly select 2 elementary schools from each of those counties. I then randomly select 2 third grade teachers in each of those schools to survey about their observations of standardized testing. Which sampling method am I using?

c) Multistage cluster sampling

I am interested in investigating why VCU students choose to use the elevator instead of stairs in a two-story building on campus. I survey every 5th student who rides the elevator. Which sampling method am I using?

c) Systematic sampling

I conduct a study on VCU students, but, when describing my results, I state that these findings apply to all emerging adults (e.g., people between the ages of 18 to 29). Which best describes the error that I am committing?

c) Misgeneralization

I want to study aggression in Veterans with combat-related PTSD. I sample only Veterans from the local VA psychiatric clinic. Which of the following best describes my sample?

c) Convenience

Why are purposive samples generally discouraged in psychological research?

c) They rely on the researcher’s judgment and may not be representative

In deciding sample size, researchers take ______ into consideration.

d) Power

Power refers to the likelihood of _________.

d) Detecting effects that really do exist

The Stall Seat Journal, which provides statistics about the prevalence of alcohol use, vaping, and other health-related behaviors among VCU students, is an example of _____ research.

b) Descriptive

I would like to investigate the characteristics of the students who enroll in PSYC 340: Introduction to the Helping Relationship. I sample students from my current classes and ask them why they chose to enroll. This is an example of _____ research.

a) Cross-sectional

Spit for Science, a project that involves collecting data from the same sample of students each year that they attend college (and for several years after!), is an example of _____ research.

a) Longitudinal

I would like to know how graduating seniors feel about entering the “real world,” and whether this viewpoint changes over time. Each year for 20 years, I randomly sample graduating seniors and ask them the same question, “What is your biggest fear about post-graduate life?” This is an example of ______.

b) Successive independent samples

It is estimated that, in the United States, approximately 25,000 people are living with a rare bone condition called Osteogenesis Imperfecta. This number represents the _____ of the disease.

c) Prevalence

Dr. Strong is advocating to get rid of his university’s IRB. He states that every researcher should decide for themselves whether their research is ethical. Dr. Strong approaches research questions using the _______ viewpoint.

a) Ethical skepticism

The panel of individuals who review research conducted at a university, hospital, or other facility to ensure that the research is conducted ethically is called a(n):

b) Institutional review board

Which of the following aspects of research would an IRB NOT be concerned with?

d) Whether the research team will likely work well together

Which of the following is TRUE regarding informed consent?

c) Informed consent may be waived as long as the study poses no more than minimal risk to participants

You want to observe how couples argue. You bribe the RA of a local dorm to sneak you into the dorm rooms of students who have significant others and install hidden cameras to capture potential arguments. This study may be considered...

d) Invasion of privacy

A research study seemingly involves two participants solving a puzzle together. In reality, one of the participants is actually a member of the research team, and they are trying to investigate how the participant reacts when the confederate sabotages the puzzle. This is an example of:

d) Deception

The best way to ensure ______ is to keep participants’ data anonymous.

c) Confidentiality

Which of the following is NOT considered a vulnerable population according to federal research laws?

b) Educators

According to federal laws, research that involves causing pain to animals can only be conducted if...

a) It can be conducted in no other way

“Peer review” refers to the process of:

a) Experts in the field reviewing papers and deciding whether or not they should be published in scientific journals

You find a strong, negative correlation between use of social media and self-esteem. Which of the following statements BEST describes your conclusion?

d) Use of social media is associated with lower self-esteem

Dr. Leslie Knope finds a moderate, negative correlation between number of salads eaten and happiness. Which best describes her findings?

a) As the number of salads eaten increases, happiness decreases

A research paper states, “Marijuana consumption and grades were correlated, r = -.54.” This indicates a:

a) Moderate negative correlation: higher marijuana consumption is associated with lower grades

A research paper states, “There was a strong correlation between ice cream eaten and happiness, in which greater ice cream consumed was associated with increased happiness.” Which correlation coefficient is most likely to represent this scenario?

b) r = .67

You find a correlation between protein consumed and satiety (feelings of fullness) of .37. Which of the following statements is true?

a) 13.7% of the variability in satiety is attributed to protein consumed

Which of the following is TRUE about statistical significance?

c) Statistical significance represents the likelihood that a correlation coefficient calculated on a sample might actually be zero in the population

Although total scores on my depression scale can range from 0-100, scores in my healthy (i.e., not depressed) sample only range from 0-30. This may indicate which of the following factors that can distort correlation coefficients?

a) Restriction of range

I would like to see if there is a correlation between gender (coded as men vs. women) and soda preference (coded as Pepsi vs. Coke). Which of the following correlation coefficients should I use?

d)Phi coefficient

I would like to see if there is a correlation between pet preference (coded as dog lovers vs. cat lovers) and income. Which of the following correlation coefficients should I use?

a) Point biserial coefficient

Which of the following is NOT one of the three ingredients of an experiment?

a) All variables measured must be on an interval/ratio scale of measurement

I am testing whether my new drug, Morgana, improves time management skills in college students. I divide my sample into groups - Group A receives a sugar pill, Group B receives 10mg of the drug, and Group C receives 20mg of the drug. Which of the following is the dependent variable in this study?

d) Time management skills

I am examining whether a phone ban improves class participation in PSYC 317. For one
week, the TA’s observe how many students participate without changing any of the
class policies. The following week, all phones are banned from the classroom, and the
TA’s again observe how many students participate. Which of the following is TRUE about
this experiment?

The equivalence of groups at the beginning of the experiment is not a concern in
this study

I want to test whether students perform better in classes with louder professors. On
Monday, students listen to a lecture by Dr. Swift, who speaks relatively quietly, and then
complete a quiz. On Tuesday, these same students listen to a different lecture by Dr.Kelce, who speaks much louder, and then complete a quiz. At the end of the
experiment, I ask the students whether or not they perceived Dr. Kelce as louder than
Dr. Swift. This question is an example of

A manipulation check

Dr. David is studying the effect of caffeine on memory. She gives participants increasing
doses of caffeine, having them perform a memory task with each additional 15mg of
caffeine that they consume. Participants improve on the memory task over time. In
addition to the caffeine, which effect might explain their improvement in performance

Practice effect

want to conduct a within-subjects experiment. However, I want to ensure that the
order in which my participants experience each condition does not impact their scores
on the dependent variable. The best way to protect against these order effects is

Counterbalancing

Systematic variance consists of all of the following excep

variance due to random error

I am testing whether college students price affects student perceptions of hamburgers.
In the experimental group, students will try two hamburgers and will be informed that
one of the burgers costs $12, whereas the other costs $25. They will then indicate which
hamburger they prefer. In the control groups, students will try the two hamburgers and
select their preference without any price information. Which of the following is NOT an
example of confound variance in this experiment?

There was a big snowstorm, and half of the participants in each condition were
unable to make it to the experiment

Attrition refers to _____, and is only a threat to internal validity when ________.

Participants dropping out of the study; more participants in one condition drop
out than in the other condition(s

In what way is a major national event, like the COVID-19 pandemic, a threat to internal
validity?

If the event impacts participants in one condition differently than it impacts
participants in the other condition(s)

really believe that my experimental therapy treatment is going to be successful; thus, I
subconsciously rate participants in the experimental group as psychologically healthier
after the experiment than I rate participants in the control group. This is an example of

Expectancy effects

I am a participant in an experiment. I think I’ve figured out the researcher’s hypothesis,
and I want to make sure that their results are helpful. Thus, I try to work really hard to
make my behavior aligned with their hypothesis. This is an example of:

Demand characteristics

Which of the following statements regarding double-blind studies is NOT true

In double-blind studies, the researcher should try to assign the participant to the
condition that the participant prefers

Which of the following statements regarding the placebo effect is NOT true?

People of higher intelligence do not demonstrate the placebo effect.