Psyc 2H Final Exam Review

regression

can be used to make prediction about 1 variable from another known variable (must have high correlation & must be linear)

describing results

comparing group percentage, correlating individual scores, comparing group means

correlation coefficient

describes how strongly variables are related to one another

ratio

equal intervals; absolute zero (ex: time, weight, length, & other physical measures); can be summarized using mean or arithmetic average

t test

examines whether 2 groups are significantly difference from each other

external validity

extent to which findings may be generalized

three claims

frequency, association, casual

features of a histogram for frequency distribution

graph title and labeled axes; bars do touch; vertical scale is frequency; numerical data

features of a bar graph for frequency distribution

graphtitle and labeled axes; bars do NOT touch, vertical scale is frequency; categorical data

inferential statistics

help make conclusions on the basis of sample data; results of a given study are based only on data obtained from a single sample of participants (not entire population); given the probability that the difference between means reflects random error rather than a real difference

interval

intervals between levels are equal in size; can be summarized using mean or arithmetic average; no absolute zero

probability

likelihood of the occurrence of some event or outcome (used in statistical inference); if probability if very low, we reject the possibility that only random or chance error is responsible for the obtained difference in means

mode (central tendency)

most frequent score; indicates central tendency when scores are measured on nominal scales

nominal

no numerical, quantitative properties; levels represent different categories or groups

degrees of freedom (df)

number of scores free to vary once the means are known

mean (M) (central tendency)

obtained by adding all the scores and dividing by the number of scores; indicates central tendency when scores are measured on an interval or ratio scales

sampling distribution

probability distribution of a given statistic based on a random sample; based on the assumption that the null hypothesis is true

ordinal

rank the levels from lowest to highest

t value

ratio of 2 aspects of data (difference between the group means & variability within groups)

purpose of regression

regression uses calculations to predict a person's score on one variable when that person's score on another variable is already known (the higher the correlation coefficient, the more accuracy in the prediction)

median (Mdn) (central tendency)

score that divides the group in hal (50% scoring below & 50% scoring above the median); indicates central tendency when scores are measured on an orginal, interval, and ration scales

pearson product-moment correlation coefficient (pearson r)

used when both variables have interval or ratio scale properties; provides info about the strength and direction of relationship; values range from 0.00 to +-1.00; can be described using scatterplots

f test or analysis of variance

used when: ➢There are more than two levels of an independent variable ➢Factorial design with two or more independent variables has been used

null hypothesis

➢H0 - Population means are equal ➢Observed difference due to random error ➢Independent variable had no effect

research hypothesis

➢H1 - Population means are not equal ➢Independent variable had an effect

statistical significance

➢Indicates that there is a low probability that the difference between the obtained sample means was due to random error ➢Reject Null hypothesis - accept research hypothesis (i.e. that the IV had an effect) (all statistical significance decisions are baed on probability distributions)

significance level

➢Researchers traditionally used a .05 or a .01 significance level in the decision to reject the null hypothesis ➢Specifies the probability of a Type I error if the null hypothesis is rejected ➢Significance level chosen and the consequences of a Type I or a Type II error are determined by the use of the results

Ratio of 2 types of variance

➢Systematic variance (between-group variance) & Error variance (within-in group variance) ➢Larger F ratio can lead to significant results

type II error

(false negative) say nothing is going on when something is (Know how alpha, sample size and effect size relate to probability of making at Type II error!)

type I error

(false positive) concludes that something is difference when it is not (Know how alpha, sample size and effect size relate to probability of making at Type I error)

_____ variance is the deviation of the individual scores in each group from their respective group means. A. Error B. Systematic C. Inferential D. Alpha

A. Error

Researchers studying the effectiveness of a diet on heart disease divided the study's participants into two groups—those with Type A personalities and those with Type B personalities. Which scale of measurement characterizes these personality variables? A. Nominal B. Ordinal C. Interval D. Ratio

A. Nominal

What does a Solomon four-group design assess? A. The impact of taking the pretest B. The significance of a simple factorial design C. The limits of external validity of a study D. The impact of independent variables under highly controlled settings

A. The impact of taking the pretest

Which of the following best describes a longitudinal study on children's development? A. The same children are tested at 1, 3, 5, and 10 years of age. B. Children belonging to the age groups 1, 3, 5, and 10 are tested simultaneously. C. Some children are tested at 1, 3, and 5 years of age while other children are tested at 3, 5, and 10 years of age. D. The children tested at 3 years of age are compared with those tested at age 5.

A. The same children are tested at 1, 3, 5, and 10 years of age.

Adrian found no significant difference in the amount of money spent on entertainment on those students who live on campus versus those who live off campus. Based on this finding, Adrian would: A. accept the null hypotheses. B. reject the null hypotheses. C. accept a Type I error. D. reject a Type I error.

A. accept the null hypotheses

The principal of a school conducts a survey to compare the number of third grade and sixth grade students who buy their lunch at school. The most appropriate way to describe the results of this survey would be to compare: A. group percentages. B. frequency polygons. C. group means. D. items purchased.

A. group percentages

Events that occur between the first and second measurement period but are not part of the manipulation are called _____ effects. A. history B. maturation C. testing D. cohort

A. history

The serious flaw associated with the nonequivalent control group design is that ____ occur. A. selection differences B. data variances C. participant dropouts D. maturation effects

A. selectrion differences

In order to study the effects of watching violent programs on children's aggressiveness, a researcher observes children's behavior after they watch 30 minutes of violent programs on television. The researcher concludes that television violence causes aggressiveness. A problem in this research is that: A. there is no control group. B. the children's behavior is not observable. C. the researcher should have had the children watch at least 60 minutes of violent programs on television. D. there is no independent variable.

A. there is no control group

A correlation coefficient is always used _____. A. to describe the strength of the relationship between two variables B. when the design of a study utilizes a correlational method C. to determine the significance of statistical analyses D. when data is collected using a nominal scale

A. to describe the strength of the relationship between two variables

One solution to the problem of generalizing to other experimenters is to use _____. A. two or more experimenters B. a field experimental technique C. computers to test participants D. quasi-experiments

A. two or more experimenters

Which of the following examples best represents the use of an interval scale? A. Ranking the participants of a race based on their performance B. Assessing students' ratings of their professors' performance on a five-point scale ranging from poor to excellent C. Measuring the number of boxes of cookies sold by scouts on the west side of a town versus those sold on the east side of the town D. Naming the different brands of cars seen in a school's parking lot

B. Assessing students' ratings of their professors' performance on a five-point scale ranging from poor to excellent

A professor at a university ranks subjects based on students' preferences identified through a survey. He ranks science first, mathematics second, and management third. What type of measurement scale has the professor employed? A. Nominal B. Ordinal C. Interval D. Ratio

B. Ordinal

Which of the following statements is true about ratio scales? A. They do not have equal intervals. B. They have an absolute zero point. C. They exhibit minimal quantitative distinctions. D. They are typically used to measure personality traits.

B. They have an absolute zero point

. _____ in quasi-experimental designs is more difficult than in true experiments because quasi-experimental designs lack the important features of true experiments such as random assignment to conditions. A. Construct validity B. Causal inference C. Propensity score matching D. Statistical regression

B. casual inference

The probability of making a Type II error increases when the: A. significance level is set very high. B. effect size is small. C. sample size is large. D. probability of a Type I error is high.

B. effect size is small

The expected value of t under the null hypothesis _____. A. equals 1 B. equals 0 C. depends on the degrees of freedom D. varies depending on the alpha level

B. equals 0

Dr. Paul found that college students between the ages of 18 and 23 performed better on a cognitive task in a low-noise condition than in a high-noise condition. Dr. Ben wants to repeat Dr. Paul's study by adding age as a variable—18-23 and 65-74. He predicts an interaction between the age and noise variables. In this case, Dr. Ben is questioning the _____ validity of the original study. A. statistical B. external C. internal D. interactional

B. external

When the independent variable has no effect on the dependent variable, the effect size statistic will: A. be equal to the degrees of freedom. B. have a value of 0.00. C. have a value of -1.0 or +1.0. D. vary depending on the alpha level

B. have a value of 0.00.

In the context of one-group pretest-posttest design, maturation effects occur when: A. taking a pretest changes the participant's behavior. B. participants change over time and become bored or fatigued. C. a confounding event occurs at the same time as the experimental manipulation. D. the basic characteristics of the measuring instrument change over time.

B. participants change over time and become bored or fatigued.

A Type I error occurs when one: A. rejects the null hypothesis when it is false. B. rejects the null hypothesis when it is true. C. accepts the null hypothesis when it is true. D. accepts the null hypothesis when it is false.

B. rejects the null hypothesis when it is true.

In a multiple baseline across situations design, _____. A. several different behaviors of a single subject are measured over time B. the same behavior is measured in different settings C. the behavior of several subjects is measured over time D. all subjects are exposed to a particular situational variable

B. the same behavior is measured in different settings

The null hypothesis is rejected whenever: A. past studies prove it wrong. B. there is a low probability that the obtained results could be due to random error. C. the independent variable fails to have an effect on the dependent variable. D. the researcher is convinced that the variable is ineffective in causing changes in behavior.

B. there is a low probability that the obtained results could be due to random error.

When comparing the differences in the ratings of responsibility for an automobile accident between male and female drivers, the null hypothesis would suggest that: A. women are more responsible drivers than men. B. there is no difference in the ratings of responsibility between male and female drivers. C. men are more responsible drivers than women. D. there is a difference in the ratings of responsibility between male and female drivers.

B. there is no difference in the ratings of responsibility between male and female drivers.

Inferential statistics _____. A. are used to generally describe the data B. are used to make conclusions about the data C. focus mainly on scales of measurement D. focus mainly on standard deviations

B. used to make conclusions about the data

Amelia realized that her 7-year-old daughter, Violet, was especially motivated by money. Amelia began a reinforcement program whereby Violet earned 5 cents every time she brushed her teeth. A month later, Amelia instituted a payment schedule of 10 cents every time Violet went to bed on time without complaining. Once these behaviors were firmly established, Violet began earning money for every book she read. What kind of singlesubject design did Amelia employ? A. Across subject multiple-baseline design B.Across behaviors multiple-baseline design C. Across situations multiple-baseline design D. Across subject ABA design

B.Across behaviors multiple-baseline design

Identify the risk associated with pretests. A. A pretest does not necessarily enable a researcher to assess mortality effects. B. A pretest does not accurately depict whether the people who withdrew were any different from those who completed the study. C. A pretest tends to induce subjects to behave differently than they would without the pretest. D. A pretest fails to provide accurate scores, although intuitively pretesting seems like a good idea.

C. A pretest tends to induce subjects to behave differently than they would without the pretest.

Professor Aaron finds that when he smiles and makes eye contact with Jeanne, she becomes more responsive to his questions. He tries the same behavior on David, Chris, and B.J. and finds that it also influences their responses to his questions. What type of single-case design did Professor Aaron employ? A.Across situations ABA design B.Across behaviors multiple-baseline design C. Across subjects multiple-baseline design D. Across subjects ABA design

C. Across subjects multiple-baseline design

Which of the following accurately describes the relationship between concepts? A. Systematic variance = error variance B. Error variance = between-groups variance C. Between-groups variance = systematic variance D. Systematic variance = within-group variance

C. Between-groups variance = systematic variance

What refers to external validity? A. Adequacy of the experimental design B. Effectiveness of the manipulation of the independent variable C. Generalizability of the research findings D. Practical application of the research findings

C. Generalizability of the research findings

A teacher displays the results of a test on a notice board. As per the results, half the students scored more than 70 percent in the test, while the remaining scored less than 70 percent. Which measure of central tendency does this scenario represent? A. Mean B. Mode C. Median D. Meridian

C. Median

Which of the following is a measure of variability? A. Mode B. Mean C. Range D. Median

C. Range

In attempting to study police officers' attitudes toward their supervisors, Alex surveys 25 police officers working in the day shift. In this case, what can help Alex ensure that his findings have external validity? A. Using a larger sample of officers working in the day shift B. Randomly assigning officers to work under specific supervisors C. Surveying officers from all shifts in the department D. Using confounding variables

C. Surveying officers from all shifts in the department

What is most likely to be true of a study conducted on a group of males to analyze the effects of room temperature on task performance? A. The study has high external validity. B. Temperature does not affect men's task performance. C. The findings of the study cannot be generalized to females. D. Task performance is a confounding variable in the study.

C. The findings of the study cannot be generalized to females.

Dana measures the height of four- and five-year-olds. To her surprise, she finds no correlation between height and age. What is most likely responsible for this result? A. Correlational methods cannot be used to calculate age and height. B. A curvilinear relationship exists between the variables. C. The range of the variables has been restricted. D. The variability in the sample will not allow the accurate calculation of a correlation coefficient.

C. The range of the variables has been restricted.

A researcher asked participants to rate the quality of two well-known brands of paper bags— Prime and Zenith. Prime was rated higher than Zenith with mean ratings of 5.50 and 3.25 respectively. This difference was statistically significant at the .05 probability level. The research hypothesis for this study suggests that: A. Prime is better than Zenith in terms of quality. B. Zenith is better than Prime in terms of quality. C. There is a difference between Prime and Zenith in terms of quality. D. There is no difference between Prime and Zenith in terms of quality.

C. There is a difference between Prime and Zenith in terms of quality.

Which of the following statements is true about bar graphs? A. They divide a whole circle, or "pie," into "slices" that represent relative percentages. B. They use bars to display a frequency distribution for a quantitative variable. C. They use a separate and distinct bar for each piece of information. D. They use a line to represent the distribution of frequencies of scores

C. They use a separate and distinct bar for each piece of information.

In an ABAB reversal design, the second "B" period is necessary to rule out: A. carry-over effects. B. correlational variables. C. chance fluctuations. D. baseline changes

C. chance fluctuation

The significance level chosen by a researcher is dependent on the _____. A. scales of measurement used for the study B. desired probability of correctly rejecting the null hypothesis C. consequences of making a Type I versus a Type II error D. type of statistic being used

C. consequences of making a Type I versus a Type II error

Single-case experiments were developed from a need to: A. have a design that examines a measurement at only one point in time. B. measure only a single dependent variable. C. determine whether a manipulation has an effect on a single research participant. D. overcome selection differences that occur in nonequivalent control group design

C. determine whether a manipulation has an effect on a single research participant.

A(n) _____ replication is an attempt to replicate precisely the procedures of a study to see whether the same results are obtained. A. abstract B. conceptual C. exact D. procedural

C. exact

When the results of a study can be generalized to other subject populations, the study is said to have _____ validity. A. statistical B. internal C. external D. construct

C. external

Aden finds that, on an average, men have higher starting salaries than women. In order to conclude that the differences in starting salaries are true differences and not a result of random error, Aden would employ the use of _____ statistics. A. qualitative B. descriptive C. inferential D. ordinal

C. inferential

Elaine has read a number of studies on the effect of physical attractiveness on the judgment of an individual's personality characteristics. She then writes a paper in which she categorizes the findings and draws conclusions based on her summaries of the studies. Elaine has most likely conducted a _____. A. categorization analysis B. meta-analysis C. literature review D. meta-categorization

C. literature review

A researcher wants to test a hypothesis according to which the mean rating of guilt will be higher for unattractive defendants than for attractive defendants. The appropriate statistical test would be the _____. A. Pearson r B. two-tailed t-test C. one-tailed t-test D. chi-square

C. one-tailed t-test

A regression equation is used to: A. determine the strength of the relationship between X and Y. B. determine the causal relationship between X and Y. C. predict a score for Y from a known score of X. D. predict the difference between the scores of X and Y.

C. predict a score for Y from a known score of X.

Sumaira took an aptitude test for a position with Accountants Unlimited. She was hired the following week. In this scenario, the predictor variable is Sumaira's _____. A. appearance and personality B. expected ability to get along with her fellow employees C. score on the aptitude test D. expected performance as an accountant

C. score on the aptitude test

Which significance level would minimize the probability of a Type I error? A. .25 B. .10 C. .05 D. .01

D. .01

To examine how a reward influences a desired behavior, a mother first counts the number of times her son makes his bed over a two-week period. For the next two weeks, she gives him a reward every time he makes his bed. Following this period, she stops rewarding him and again counts the number of times he makes his bed. This procedure would be an example of a(n) _____ design. A. pretest-posttest B. baseline treatment C. control series D.ABA

D. ABA

Which of the following are two general methods for studying individuals of different ages? A. Multiple baseline and single-case experimental designs B. Quasi-experimental and nonequivalent control group designs C. Interrupted time series and control series designs D. Cross-sectional and longitudinal research designs

D. Cross-sectional and longitudinal research designs

A student is interested in the effect of environmental conditions on task performance. She makes participants complete a series of math problems under different conditions of temperature—cold, warm, and hot, and different noise conditions—quiet and noisy. The most appropriate test to analyze the data would be a(n) _____. A. t-test B. Pearson r C. chi-square D. F-test

D. F test

Dr. Jayden is studying the effect of exercise on cholesterol level. He first measures his patients' cholesterol level before recommending an exercise program and after one month of participating in an exercise program, he measures their cholesterol level again. What type of research design has Dr. Jayden employed? A. Between groups design B. One-shot case study C. Missing control group design D. One group pretest-posttest design

D. One group pretest-posttest design

A graduating college student takes the Graduate Record Exam and scores high marks. Six months later the student retakes the exam after completing all undergraduate coursework, but scores relatively low. Other than the boring coursework, what is most likely to account for the lower scores? A. Maturation B. Testing C. Instrument decay D. Regression toward the mean

D. Regression toward the mean

Which of the following describes a sequential design? A. Studying a group of 5 year olds over a 10 year period B. Comparing reasoning abilities of 5, 8, and 10 year-olds C. Measuring motor abilities of a child when she is 2 years old and then measuring her abilities again when she is 5 years old D. Studying groups of 10- and 15-year-olds, and then studying these individuals 2, 4, and 6 years later

D. Studying groups of 10- and 15-year-olds, and then studying these individuals 2, 4, and 6 years later

Why are conceptual replications considered important in the field of social sciences? A. They allow statistical conclusions and identify trends in the literature. B. They take into consideration the fact that prior findings are a prerequisite for conceptual replications to occur. C. They allow researchers to precisely replicate the procedures of a study to see whether the same results are obtained. D. They use complex variables that can be operationalized in different ways.

D. They use complex variables that can be operationalized in different ways.

Ethan concludes that there is no difference in the driving ability of drivers who have consumed one can of beer and those who have consumed three cans of beer. However, there actually is a difference in the driving ability of the drivers. In this case, Ethan has made a(n) _____ error. A. null B. alpha C. Type I D. Type II

D. Type II

A Type II error occurs when one: A. rejects the null hypothesis when it is false. B. rejects the null hypothesis when it is true. C. accepts the null hypothesis when it is true. D. accepts the null hypothesis when it is false.

D. accepts the null hypothesis when it is false.

In a cross-sectional study, a difference among groups of different ages may reflect developmental age changes; however, these differences may result from _____ effects. A. regression B. nonequivalent C. propensity D. cohort

D. cohort

A researcher replicates a past study that manipulates the physical attractiveness of a defendant by using photographs instead of written descriptions. This technique would be an example of _____ replication. A. procedural B. abstract C. exact D. conceptual

D. conceptual

Statistically, significant results mean that the results are: A. very important. B. meaningless. C. likely to be due to chance differences between the groups. D. likely to be due to true differences between the groups.

D. likely to be due to true differences between the groups.

When testing the differences between means, the null hypothesis suggests that any observed difference is due to _____. A. manipulation B. systematic variance C. error variance D. random error

D. random error

With respect to Pearson r, the absolute size of r is the coefficient that indicates the: A. direction of the relationship between two variables. B. measurement scale that applies to two variables. C. curvilinear relationship between two variables. D. strength of the relationship between two variables.

D. strength of the relationship between two variables.

power of statistical test

Determines optimal sample size based on probability of correctly rejecting the null hypothesis

descriptive statistics

allows researches to make precise statements about the data; need 2 statistics to describe data and summarize the info contained in a frequency distribution; 1. central tendency (how participants scored overall) 2. variability (hwo widely the distribution of scores is spread)