Question 1

The diagnostic accuracy of a test is sometimes called the _________ of a diagnostic test.
A)likelihood
B)sensitivity
C)specificity
D)efficiency

Accepted Answer

The diagnostic accuracy of a test refers to its efficiency in correctly identifying those with and without the disease. Efficiency encompasses both the sensitivity (true positive rate) and specificity (true negative rate) of a test, providing a holistic view of its diagnostic performance.

Question 2

Which of the following is not true of factor analysis?
A)there are an infinite number of correct solutions
B)it can be used to reduce the number of items on a test or measure
C)factor analysis designs are similar to ANOVA designs
D)in IQ research, it found a single "g" factor

Accepted Answer

Factor analysis is a statistical method used for identifying underlying variables, or factors, that explain the pattern of correlations within a set of observed variables. It does not have designs similar to ANOVA (Analysis of Variance), which is used for comparing the means of three or more samples. Factor analysis focuses on reducing data dimensionality and uncovering structure in the relationships between variables, not on comparing group means.

Question 3

A false negative is defined as
A)a test result is positive, and the patient actually has the condition
B)a test is negative, and the patient actually has the condition
C)a test is positive, and the patient doesn't have the condition
D)a test is negative, and the patient doesn't have the condition

Accepted Answer

A false negative occurs when a test result indicates that a person does not have a condition when, in fact, they do.

Question 4

A true negative is defined as
A)a test result is positive, and the patient actually has the condition
B)a test is negative, and the patient actually has the condition
C)a test is positive, and the patient doesn't have the condition
D)a test is negative, and the patient doesn't have the condition

Accepted Answer

A true negative occurs when a test result is negative, indicating the patient does not have the condition, and this result is accurate because the patient indeed does not have the condition.

Question 5

A false positive is defined as
A)a test result is positive, and the patient actually has the condition
B)a test is negative, and the patient actually has the condition
C)a test is positive, and the patient doesn't have the condition
D)a test is negative, and the patient doesn't have the condition

Accepted Answer

A false positive occurs when a test indicates that a condition or trait is present when it is not, hence option C is correct.

Question 6

Which of the following is true about a multivariate analysis of variance?
A)one or more independent variables, one or more dependent variables
B)two or more independent variables, with one or more levels of each independent variable
C)one or more independent variables, two or more dependent variables
D)all of the above are true

Accepted Answer

Multivariate analysis of variance (MANOVA) involves one or more independent variables and two or more dependent variables.

Question 7

Shrinkage in linear discriminant function analysis can be minimalized by
A)having the number of participants in the smallest group be 10 times the number of predictor variables
B)having the number of participants in the largest group be 10 times the number of predictor variables
C)having the number of participants in the smallest group be at least 30
D)having the number of participants in both groups be at least 150

Accepted Answer

Shrinkage in linear discriminant function analysis is minimized when the sample size is large relative to the number of predictor variables. Specifically, having the number of participants in the smallest group be 10 times the number of predictor variables helps ensure that the model is not overfitting to the sample data, thus reducing shrinkage.

Question 8

A test possesses good specificity if it has a
A)high true-positive rate
B)high true-negative rate
C)high false-positive rate
D)high false-negative rate

Accepted Answer

Specificity measures the proportion of actual negatives that are correctly identified as such (e.g., the percentage of healthy people who are correctly identified as not having the condition). Therefore, a test with high specificity has a high true-negative rate, meaning it accurately identifies those without the disease.

Question 9

Which of the following is not true about MANCOVA?
A)handles more than one dependent variable
B)covaries one or more nuisance variables
C)handles one or more independent variables
D)covaries only one confounding variable but one or more nuisance variables

Accepted Answer

MANCOVA (Multivariate Analysis of Covariance) can covary more than one confounding variable in addition to one or more nuisance variables, making option D incorrect as it suggests MANCOVA can only covary one confounding variable.

Question 10

A test possesses good sensitivity if it has a
A)high true-positive rate
B)high true-negative rate
C)high false-positive rate
D)high false-negative rate

Accepted Answer

A test with good sensitivity is able to correctly identify those with the condition (true positives), meaning it has a high true-positive rate.

Question 11

In linear discriminant function analysis, the criterion variable
A)is usually dichotomous
B)is usually continuous
C)is an a priori assumption by the experimenter
D)all of the above
E)a and c

Accepted Answer

In linear discriminant function analysis, the criterion variable is usually dichotomous, meaning it is typically divided into two distinct groups or categories. Additionally, the choice of the criterion variable is an a priori assumption by the experimenter, meaning it is decided upon before the analysis based on theoretical or practical considerations.

Question 12

A true positive is defined as
A)a test result is positive, and the patient actually has the condition
B)a test is negative, and the patient actually has the condition
C)a test is positive, and the patient doesn't have the condition
D)a test is negative, and the patient doesn't have the condition

Accepted Answer

A true positive occurs when a test correctly identifies a condition that is present in the patient.

Question 13

The statistical object of cluster analysis is to minimize _______ variation and maximize variation between _________.
A)within-group; groups
B)group; subjects
C)subject; confounding variables
D)trend; cycles

Accepted Answer

Cluster analysis aims to minimize within-group variation, meaning it seeks to make the items within each cluster as similar as possible, and maximize variation between groups, meaning it seeks to make the clusters as distinct from each other as possible.

Question 14

Which of the following is true of multivariate statistics?
A)almost always computed by computer programs
B)can be easily computed by the average calculator
C)there are few debates about their use and interpretation
D)all of the above are true

Accepted Answer

Multivariate statistics involve complex calculations that are beyond manual computation for practical purposes, thus they are almost always computed by computer programs. Calculators typically cannot handle these complex calculations, and there are significant debates about the use and interpretation of multivariate statistics, making options B and C incorrect.

Question 15

Which of the following is not true of ANCOVA?
A)covaries the effect of one or more nuisance variables
B)covaries the effect of one or more nuisance variables on the independent variable
C)covaries the effect of one or more nuisance variables on the dependent variable
D)covaries the effect of one or more confounding variables

Accepted Answer

ANCOVA (Analysis of Covariance) primarily covaries the effect of one or more nuisance or confounding variables on the dependent variable, not on the independent variable. Its main purpose is to control for the effects of these extraneous variables on the dependent variable to more accurately estimate the effect of the independent variable(s) of interest.

Question 16

The number of new verified cases of a disease in a year is called
A)prevalence
B)incidence
C)likelihood
D)number of new cases

Accepted Answer

Incidence refers to the number of new cases of a disease that occur in a specified population within a defined time period, typically a year.

Question 17

If a patient is harmed or killed just by the treatment for a disease, it is called the ____________ effect.
A)not too good
B)bad
C)iatrogenic
D)polygenic

Accepted Answer

The term "iatrogenic" refers to any effect, especially a negative one such as harm or death, that results directly from a medical treatment or intervention, rather than from the underlying disease itself.

Question 18

Canonical correlation comes closest to being a technique related to
A)correlation
B)regression
C)factor analysis
D)all of the above

Accepted Answer

Canonical correlation is a multivariate statistical technique that can be seen as related to all of the mentioned techniques: correlation, because it measures the relationship between two sets of variables; regression, because it can predict one set of variables from another; and factor analysis, because it can be used to identify latent variables that explain the correlation between the sets of variables.

Question 19

To have a reliable factor analysis of 57 items, the study should be conducted on at least ________ people.
A)57
B)285
C)570
D)1140

Accepted Answer

A common rule of thumb for factor analysis is to have at least 10 participants per item, so for 57 items, at least 570 participants are needed.

Question 20

Signal detection theory can be graphically represented by a
A)scatterplot
B)receiver operating curve
C)histogram
D)bar graph

Accepted Answer

Signal detection theory is often graphically represented by a receiver operating characteristic (ROC) curve, which plots the true positive rate against the false positive rate at various threshold settings.

Quiz 16: Other Statistical Parameters and Tests

The diagnostic accuracy of a test is sometimes called the _________ of a diagnostic test.

Which of the following is not true of factor analysis?

A false negative is defined as

A true negative is defined as

A false positive is defined as

Which of the following is true about a multivariate analysis of variance?

Shrinkage in linear discriminant function analysis can be minimalized by

A test possesses good specificity if it has a

Which of the following is not true about MANCOVA?

A test possesses good sensitivity if it has a

In linear discriminant function analysis, the criterion variable

A true positive is defined as

The statistical object of cluster analysis is to minimize _ variation and maximize variation between ___.

Which of the following is true of multivariate statistics?

Which of the following is not true of ANCOVA?

The number of new verified cases of a disease in a year is called

If a patient is harmed or killed just by the treatment for a disease, it is called the ____________ effect.

Canonical correlation comes closest to being a technique related to

To have a reliable factor analysis of 57 items, the study should be conducted on at least ________ people.

Signal detection theory can be graphically represented by a