final

A scatter plot shows a set of data points that are clustered close to a line that slopes down to the right. Which value would be closest to the correlation for these data?

-0.8

If a between-subjects experiment produces 50 scores in treatment 1 and 50 scores in treatment 2, then the experiment must have employed ____.

100 participants

Which sampling technique is most likely to result in a biased sample?

Convenience Sampling

A researcher recruits a sample of 25 preschool children for a research study by posting an announcement in a local daycare center describing the study and offering a $10 payment for participation. What kind of sampling is the researcher using?

Convenience sampling

An advantage of between-subjects designs is that they require fewer participants than are typically needed for within-subjects designs.

False

In a between-subjects experiment, increasing the variance within treatments increases the likelihood of finding significant differences between treatments.

False

In a distribution with a mean of M = 36 and a standard deviation of SD = 8, a score of 40 would be considered an extreme value.

False

In an experiment, the process of manipulation involves changing the value of the dependent variable from one treatment condition to another.

False

It is always necessary to have at least 25-30 participants in a study

False

It is widely considered ethical to coerce participants to participate in a study if the research findings could be very beneficial to society.

False

Research studies consistently demonstrate that debriefing participants effectively eliminates the problems caused by deception.

False

Since convenience sampling offers no guarantee of a representative and unbiased sample, it should not be used in behavioral research.

False

The case study design can be used to establish causal relationships between variables.

False

The Spearman correlation is used when both scores are _____.

From the ordinal scale

Why is a confounding variable unacceptable in a true experiment?

It threatens internal validity by providing an alternative explanation for the results.

To select a sample of 10 employees from a factory workforce of 100, a researcher puts each employee's name on a slip of paper, then shuffles the papers in a hat and randomly picks 10 names. What kind of sampling is being used?

Probability

When comparing means in a single-factor multiple group design, which statistical analysis is most appropriate?

Single-factor analysis of variance

What is a big advantage of using a multiple-treatment design?

The data can provide more in-depth information about the relationship between the independent and dependent variables.

A disadvantage of holding a variable constant is that it limits an experiment's external validity.

True

A matched-subjects design attempts to gain the advantages of a within-subjects design, although it actually compares different groups of participants.

True

A researcher intends to compare two different treatment conditions. Participants for the first treatment are selected and tested early in the school semester, and participants for the second treatment are selected and tested late in the semester. In this study, the time-of-testing represents a confounding variable.

True

A researcher knows that there is a relationship between obesity and watching television for young children. However, it is not known whether children watch more TV because they are overweight, or whether they are overweight because they watch so much TV. This is an example of the directionality problem.

True

A researcher reports a significant correlation using an alpha level of .01. The probability that the researcher is making a Type I error is p < .01.

True

Both correlational studies and differential research examine the relationship between two variables.

True

Deliberately putting inaccurate information in a research report is an example of fraud.

True

Differential attrition can threaten the internal validity of a between-subjects experiment.

True

For a within-subjects experiment, one advantage of a two-treatment design compared to a multiple-treatment design is that it is easier to counterbalance.

True

It is always possible that patterns observed in sample data do not accurately represent patterns in the population.

True

Research results show that participants who shout their favorite curse words over and over can endure a painful stimulus longer than participants who shout a neutral word. For this study, the dependent variable is the amount of time that the pain is endured.

True

Researchers use random assignment in an effort to create groups that are as similar as possible.

True

Simple random sampling without replacement means that the likelihood of selecting one specific individual will depend on which other individuals are selected for the sample.

True

The purpose of an experiment is to demonstrate that changes in one variable are responsible for causing changes in a second variable.

True

If there are many individual differences that could confound your study, what is the best approach for creating equivalent groups in that case?

Using random assignment

Dr. Jones systematically varies the brightness in the laboratory (400, 800, and 1600 lumens) while holding other variables constant, and observes that the participants' activity level decreases as the brightness decreases. This illustrates ____.

a causal relationship between brightness and activity level

A researcher who tells participants that a study is about group decision-making rather than how people cave to peer pressure is committing ____.

active deception

What is the most common statistical analysis for a single-factor two-group design (hint: you are comparing two groups to see if they are different).

anova

In an experiment, manipulation of the independent variable requires ____.

creating at least 2 treatment conditions defined by 2 different levels of the independent variable

Increasing variance within groups ____ the likelihood of finding a difference between the treatment conditions.

decreases

A researcher reports a positive relationship between sugar consumption and activity level for a group of eight-year-old children. However, the researcher cannot be sure whether the extra sugar is causing the children to be more active or whether the extra activity is causing the children to eat more sugar. This is an example of the ____.

directionality problem

The primary advantage of a stratified random sample is that it ____.

ensures that group sizes will be adequate for statistical analysis

The Tuskegee study involved ____.

failing to provide treatment for men with syphilis

The ____ method for quantifying observations involves counting the number of times a behavior occurs in a specified period of time.

frequency

A major goal of research is to ____ from a small group of participants included in a study to the larger group from which they came.

generalize

One responsibility of the Institutional Review Board (IRB) is to ensure that ____.

human participants will be kept safe in research

Researchers typically try to ____.

increase the differences between treatments and decrease the variance within treatments.

For a within-subjects study comparing two treatments, A and B, a researcher expects that practice in the first treatment will improve the participants' scores in the second treatment. If the order of treatments is counterbalanced, then the practice will ____.

influence scores in treatment A for half the participants and scores in treatment B for half the participants

Holding a participant characteristic (such as age or gender) constant strengthens ____ and weakens ____.

internal validity; external validity

A variable measured on the nominal scale of measurement is akin to:

label data NOT NUMERICAL

The specific treatment conditions that are used in an experiment are called the ____.

levels of the independent variable

In a within-subjects study that extends over a relatively long time, it is possible that there will be systematic changes in the participants' skills or knowledge during the time of the study. When these changes influence the participants' scores, causing scores at the end of the study to be different from scores at the beginning, the effect is called ____.

maturation

If a frequency distribution is shown in a bar graph, what scale was used to measure the scores?

nominal or ordinal

In a between-subjects design, ____.

only one score is obtained for each participant

The tendency for individuals who have extreme scores (high or low) on one measurement and to have less extreme scores on a second measurement is called ____.

regression toward the mean

When a sample has the same characteristics as the target population, the sample is said to be a(n) ____ sample.

representative

In a between-subjects design, the separate groups must be as ____.

similar in participant characteristics as possible.

In an experiment, participants are randomly assigned to treatment conditions ____.

to help protect the internal validity of the study

Measuring levels of circulating cortisol (a stress hormone) is an example of operationally defining the variable Stress.

true

The tendency for extremely high scores on one measurement to be followed by lower scores on a second measurement is called statistical regression.

true

Using a simple random sample eliminates bias from the selection process.

true

The concept of degrees of freedom is associated with the ____.

variance for a sample

If the data in a scatter plot form a nearly perfect circle, the Pearson correlation would be approximately ____.

zero