Deck 8: Research Stats

Question 1

What does cluster sampling refer to, in the context of increasing the external validity of a study?

A)It ensures proportional representation.
B)The sampling unit is a naturally occurring group.
C)It ensures a sample representative of the population.
D)Subjects do not know which group they are in.

Answer 1

The sampling unit is a naturally occurring group.

Question 2

Different research designs and strategies are used to gain specific types of information. How does correlational research work?

A)Investigators assign subjects to groups at random and they receive different levels of a variable.
B)Investigators can't infer causal relationships.
C)Variables are assessed as a function of time.
D)Investigators use naturally occurring groups.

Answer 2

Investigators can't infer causal relationships.

Question 3

Frequency distribution provides a summary of a data set and indicates number of cases at any given score within a given range. Which of the following statements refers to skewed distribution?

A)It has asymmetrical frequency distributions.
B)It is known as the bell-shaped curve.
C)It is most often used for a high number of data points.
D)Half the data fall above the mean and half fall below it.

Answer 3

It has asymmetrical frequency distributions.

Question 4

In statistics, standard error of the mean refers to the expected error of a given sample mean. Which of the following statements is not true about standard error of the mean?

A)The score increases as N decreases.
B)It is the extent to which a sample mean can be expected to deviate from the corresponding population mean.
C)We know that one mean is greater or less than another mean.
D)The score can be expected to deviate +/- SE mean points from the population mean.

Question 5

There are three main types of group design in research. Which design sometimes requires the process of counterbalancing?

A)Between groups design
B)Mixed design
C)Passive design
D)Within subjects design

Question 6

Single-subject design in research studies one or a few subjects closely, rather than studying groups. What is one of the most common problems associated with single subject design?

A)Autocorrelation
B)Non-manipulation
C)Carryover effects
D)Cohort effects

Question 7

Research aims to draw conclusion about relationships among variables. There are a number of threats to validity-factors that interfere with making reliable and clear conclusions. Which of the following concerns is a threat to internal validity?

A)Instrumentation
B)Demand characteristics
C)Sample characteristics
D)Experimenter expectancies

Question 8

There are four types of data resulting from research that determine what kind of statistical test is used in analysis. What type of data involves obtaining numerical scores for each individual in a study, such as weight or age, where scores have an absolute zero?

A)Nominal data
B)Ordinal data
C)Ratio data
D)Interval data

Question 9

Descriptive statistics is used to describe the data collected from a group (the dependent variables). Group data is described using measures of central tendency. Which of those measures is the arithmetic average of a group's data?

A)Mean
B)Median
C)Mode
D)Range

Question 10

In addition to being measured by central tendency, group data can be measured by variability in descriptive statistics. The standard deviation from the mean is a measure of average deviation from the mean in a set of scores. Which of the following sets of scores will have the greatest standard deviation?

A)3, 7, 10
B)15, 17, 23, 27
C)4, 7, 8, 20
D)4, 7, 8, 10

Question 11

Graphs are sometimes used to represent a group's data in descriptive statistics. On a graph, the X-axis always represents categories or scores and the Y-axis always represents frequency. Interval and ratio data are depicted the same way on graphs; how are those two types of data graphed?

A)Bar graph
B)Rectangular or linear graph
C)Curved graph
D)Histogram

Question 12

Inferential statistics procedures are used to make inferences about the general population from a study sample. Research in this field is based on a hypothesis that applies to the population and is tested using a sample. There are different types of hypotheses used in research. Which of those states that the independent variable has no effect on the dependent variable?

A)Alternative hypothesis
B)Null hypothesis
C)Rejection hypothesis
D)Zero effect hypothesis

Question 13

The central limit theorem discusses the relationship between sample size (assuming an infinite number of equally-sized samples) and mean distribution of those samples on a graph. According to the theorem the standard deviation of the means will equal what?

A)The standard deviation of the population
B)The standard deviation of the population divided by number of samples
C)The standard deviation of the population divided by the square root of sample size
D)The population mean divided by the square root of sample size

Question 14

In an experiment designed to enhance IQ with a sample size of 25, where population mean for IQ is 100, what would be considered a statistically insignificant sample mean IQ?

A)99
B)110
C)95
D)105

Question 15

In hypothesis testing, the area of the curve in which it is unlikely a researcher will obtain means is called the rejection region (or region of unlikely values). What conclusions are drawn when obtained values fall in the rejection region?

A)The experiment was unsuccessful and needs to be redesigned
B)Null hypothesis is rejected; there are differences between groups
C)Null hypothesis is rejected; there are no statistically significant differences between groups
D)Null hypothesis is accepted; there are no statistically significant differences between groups

Question 16

Z-scores are a type of standard score (scores based on the standard deviation of the sample). Why is it useful to transform raw scores into z-scores?

A)To normalize distribution of a sample
B)To determine population parameters
C)Because they correspond to percentile ranks
D)Because they can be used to calculate standard error of the mean

Question 17

Two students take a test. Student F scores in the 92nd percentile and student K scores in the 47th percentile. If three points are added to each student's raw score, whose percentile will be more impacted?

A)Student K
B)Student F
C)Both students K and F
D)Neither student

Question 18

A study collects information from 50 people about their ethnicity, where options are Caucasian, Hispanic, Native American, Asian, and African; and their religious views, where options are agnostic, Christian, atheist, and other. How many degrees of freedom are there?

A)9
B)12
C)20
D)3

Question 19

When analyzing a one-way ANOVA, what value is used to determine significance?

A)Standard error of the mean
B)F ratio
C)t-scores
D)Percentiles

Question 20

In statistical test construction, factorial design allows for analysis of the effect of each factor on the response variable, as well as the effect of interactions between factors on the response variable. If a factorial design yields main and interaction effects, how should results be interpreted?

A)Analyze the main effect in light of the interaction effect
B)Analyze the main effect and interaction effect together
C)Analyze the interaction effect independently
D)Analyze all effects independently

Question 21

Tests of relationship and predication are divided into bivariate and multivariate tests. Bivariate correlations look at the relationship of two variables-one is a predictor and the other is the criterion. What does the correlation coefficient describe?

A)The effect of the predictor variable on the criterion variable
B)The effect of the predictor variable on the criterion variable in terms of strength and direction
C)The relationship between the predictor variable and the criterion variable in terms of strength and direction
D)The relationship between the predictor variable and the criterion variable in terms of absolute value

Question 22

One of the values used in bivariate correlation tests is the coefficient of determination. If there is a correlation coefficient of .50 between education and income, what is the coefficient of determination?

A)0.5
B)0.25
C)0.07
D)75%

Question 23

Test construction requires that tests have both validity and reliability. What is the Spearman-Brown prophecy formula used for in this context?

A)To predict increase in reliability if a test were longer than it is
B)To predict reliability of a speeded test
C)To predict criterion-related validity of a test score
D)To predict if standard error of measurement is useful

Question 24

Multiple regression tests are used when there are several predictors (or independent variables) and one or more criterion (dependent variables). What does multicollinearity refer to?

A)Predictors are highly correlated, and therefore redundant
B)Predictors are too lowly correlated to be useful
C)Criterion are highly correlated, and therefore redundant
D)There is a high correlation between each predictor and criterion

Question 25

Professor Plum just finished scoring the midterms of the 15 students in his statistics class. He put these results on the blackboard for the entire class to see:
100% 3 students
90% 4 students
80% 1 student
70% 7 students
Then he asked the one student who got 80% whether his score was the mean, median, mode, or some combination thereof. The bewildered student answered "I don't have a clue!" Can you pick the correct answer from the following four choices?

A)80 is the mean, but not the median or the mode.
B)80 is the median, but not the mean or the mode.
C)80 is the mode, but not the mean or median
D)80 is the mean and median, but not the mode.

Question 26

Which of the following statements about scientific research studies is the most accurate?

A)If the hypothesis is confirmed, the study is considered valid.
B)If the hypothesis is not confirmed, the study is considered invalid.
C)No study can be considered valid unless it is replicated.
D)It is impossible to control for every variable, so if one looks hard enough, a flaw can be found in almost any study.

Question 27

Suppose you were given the results of a large sample of 11-year-old students, all of whom were given the 4th Edition of the Wechsler Intelligence Scale for Children (WISC-IV). The data were analyzed and, unsurprisingly, a statistically significant correlation was found between scores on the Vocabulary subtest of the WISC-IV and WISC Total IQ. A statistically significant correlation was also found between WISC-IV Vocabulary scores and total years of parents' schooling. What do these findings tell you?

A)The higher the parents' level of education, the higher the IQ of the child.
B)Children with good vocabularies have higher IQ scores than those with more limited vocabularies.
C)Parents who hire a tutor to help improve their child's vocabulary will derive another benefit-a boost in their child's IQ score.
D)None of the Above.

Question 28

What type of information would you not ordinarily find included in the manual accompanying a standardized test?

A)A set of norms obtained with certain well-defined subgroups of examinees.
B)Statistical evidence pertaining to the test's reliability and validity.
C)Guidelines for test users on how to use the test to conduct their own test validation study.
D)Information about alternate forms and formats of the test and either their interchangeability or preferred intended use.

Question 29

If the scores on a particular test fit the normal bell shaped curve distribution, what percentage of scores should fall between +2 and - 2 standard deviations from the mean?

A)Less than 50%
B)About 68%
C)About 95%
D)More than 99%

Question 30

Psychologists often rely on rating scales for the assessment of children's behavior. One potential problem with rating scales is known as the "halo effect." Which of the following scenarios best describes ratings possibly contaminated by the halo effect?

A)A child receives a 4 out of 5 rating on one area of personality functioning and receives the same rating on every other area of personality functioning.
B)A child was evaluated with a rating scale the year before and was rated 4 out of 5 on a particular area of behavior. The same rating scale is used on the same child a year later, and the rating remains the same.
C)Two children are rated by the same person with the same rating scale. The first child receives high ratings, and so does the second child.
D)Two children are rated by the same person with the same rating scale. After giving a poor rating to one child, the rater, not wanting to have poor ratings across the board, gives another child a high rating.

Question 31

All of the students in Dr. Wright's psychology class had to conduct their own research study and prepare a report describing it. The instructor, after carefully reading all of the papers, gave one of the following students an A. The remaining three students all got lower grades. Based solely on the information given here, who was the happy student who got an A?

A)Danielle, whose study with 16 ethnically diverse students confirmed her hypothesis.
B)Janelle, whose study with 60 private school students on the relationship between IQ and grade point average confirmed her hypothesis.
C)Lydell, whose report included an in-depth discussion of the methodological flaws which might have contributed to the non-confirmation of his hypothesis.
D)Tyrell, whose paper was seven pages long, in comparison to the other students' papers which were at least twice that length.
E)Not enough information to determine.

Question 32

A study showing evidence of substantial correlations between the scores of two alternate forms of the same test, with half of the subjects given one form first and half given the other form first, would be evidence of what?

A)Reliability
B)Validity
C)Halo effect
D)Practice effect

Question 33

The statistical technique known as item analysis provides information about what aspect of a test's utility?

A)Ceiling
B)Internal consistency
C)Face validity
D)Correction for faking

Question 34

If a study shows statistically significant differences between the MMPI-A scores of adolescents in a psychiatric hospital and those of adolescents who are not hospitalized, the findings would be evidence of what type of validity?

A)Content validity
B)Construct validity
C)Concurrent validity
D)Predictive validity