Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AU13 - Evaluative Final > Final Exam Review Lecture > Flashcards

Final Exam Review Lecture Flashcards

1
Q

What is the difference between efficacy and effectiveness?

A
  • efficacy - the extent to which a specific procedure produces a beneficial result under ideal conditions
  • effectiveness - measure of the extent to which a specific procedure, when deployed in the field in routine circumstances, does what it is intended to do for a population; “how it works in the real world”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a nominal scale of measurement? Give an example.

A
  • process of categorization

- gender, political party, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an ordinal scale of measurement? Give an example.

A
  • measurement scale based on the classification of an observation according to its relationship to other observations; numbers not to scale
  • poor-fair-good rating, etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a continuous scale of measurement? Give an example.

A
  • interval or ratio; scale with equal units of measurement

- temperature, mass, time, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What scale of measurement is best described by mode?

A

nominal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What scale of measurement is best described by mean?

A

continuous (interval/ratio)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What scale of measurement is best described by median?

A

ordinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the term for the number of observations that are “free to vary”?

A

degrees of freedom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference between standard deviation (SD) and standard error (SE)?

A
  • standard deviation - used to measure the variability of individual subjects around a sample mean
  • standard error - used to assess how accurately a sample mean reflects a population mean
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the Central Limit Theorem.

A

In random samples of N observations drawn from a population with a mean (M) and a standard deviation (S), the sample means will be approximately normally distributed with a mean equal to M and a standard deviation equal to (S)/SQRT(N).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the purpose of significance?

A

allows us to make inferences about the population from which our samples are drawn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

As sample size increases, error ______.

A

decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the difference between a research hypothesis, null hypothesis, and alternative hypothesis?

A
  • research hypothesis - language-based statement of what we are trying to prove
  • null hypothesis - mathematical statement of no difference
  • alternative hypothesis - mathematical statement that there is a difference; covered everything the null doesn’t
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Type I error? What is this also called?

A
  • saying there are effects when there are none

- alpha, p-value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Type II error? What is this also called?

A
  • saying there is no effects when there are

- beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the relationship between alpha and beta?

A

inversely proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

As sample size increases, alpha and beta ______.

A

decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is power?

A
  • rejecting the null hypothesis when the null hypothesis is false (saying there is a difference when there actually is a difference)
  • in other words, the likelihood that you will find a difference if a difference exists
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If alpha increases, beta ______, and power ______.

A
  • beta decreases

- power increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If sample size increases, alpha ______, beta ______, and power ______.

A
  • alpha decreases
  • beta decreases
  • power increases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Name the hierarchy of evidence quality in order.

A
  1. systematic reviews and meta-analysis
  2. clinical trial in humans (all criteria met)
  3. clinical trial in humans (most criteria met)
  4. longitudinal cohort studies
  5. case-control studies
  6. descriptive and cross-sectional studies
  7. case reports and case series
  8. personal opinions, subjective impressions, and anecdotal accounts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the difference between a dependent and independent variable?

A
  • dependent variable - variable we measure and compare

- independent variable - variable we manipulate or the “grouping variable”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a one-sample t-test used to determine?

A

to determine if your sample is different from a specific population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When doing a two-sample t-test, how does the calculation of degrees of freedom change from doing a one-sample t-test?

A

one-sample t-test:
df = N - 1
two-sample t-test:
df = N1 + N2 -2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a two-sample t-test used to determine?

A

whether the two groups (a control and experimental group, for example) are different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When doing a two-sample t-test, how does the calculation of standard deviation change from doing a one-sample t-test?

A

one-sample t-test:
SD = SQRT(SS/df)
two-sample t-test:
SD = SQRT((SS1+SS2)/df)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the assumptions/requirements of a t-test?

A
  • continuous measurement scale
  • samples are drawn from populations with normal distributions
  • samples are drawn from populations with equal variances
  • the samples are independent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

If a t-test fails to demonstrate significance, what 2 reasons could explain this?

A
  • it is the truth (the populations aren’t different)

- the sample size is too small to show a difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the impact factor?

A

the total number of citations to articles appearing in the journal divided by the total number of articles published

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a longitudinal cohort study?

A

group of individuals defined on the basis of exposure to a suspected risk factor of disease; when study starts, subjects are free of disease

31
Q

What is a case-control study?

A

subjects selected on the basis of whether they do or do not have a particular disease

32
Q

What is a descriptive and cross-sectional study?

A

“snapshot” in time; disease and exposure assessed at the same time in a well-defined group; may not always be possible to distinguish whether the exposure preceded or followed the disease

33
Q

What is a case report?

A

describes the experience of a single patient/individual or groups with a similar diagnosis; may lead to formulation of a hypothesis

34
Q

What is a case study?

A

collection of individual case reports

35
Q

What do descriptive studies describe?

A

describe patterns of disease occurrence in relation to persons, places and time

36
Q

How is chi square calculated?

A

(observed - expected)^2/(expected)

37
Q

What are the assumptions for chi square?

A
  • both groups are composed of nominal or ordinal data
  • both groups are independent
  • all categories are mutually exclusive
  • all expected frequencies are >5
38
Q

What is the difference between reliability and validity?

A
  • reliability - how consistent or reproducible observations or measurements are
  • validity - how closely your observations, measurement instrument or measurements are to the actual or accepted values
39
Q

What is the reliability coefficient also called?

A

kappa

40
Q

What is the equation to calculate the reliability coefficient (kappa)?

A

K = (PO - PE)/(1-PE)

PO = observed agreement
PE = expected agreement
41
Q

What are the advantages of a case-control study?

A
  • allows study of diseases with long latency periods
  • efficient in time and cost
  • allows for adequate numbers of diseased and non-diseased individuals to be identified
  • evaluation of rare disease
  • can evaluate a wide range of potential etiologic exposures and the interrelationships among them
42
Q

What are the disadvantages of a case-control study?

A
  • disease and exposure have already happened when participant is entered into study
  • susceptible to bias
    • selection bias
    • recall bias (different reporting)
43
Q

What is a case-control study used for?

A
  • test a specific hypothesis

- explore a range of exposures among affected or non-affected individuals

44
Q

What are the three types of cohort study?

A
  • prospective
  • retrospective
  • both prospective and retrospective
45
Q

What is the definition of relative risk (risk ratio)? What is its equation?

A
  • likelihood of developing the disease in the exposed group relative to those not exposed
  • RR = (incidence in exposed group)/(incidence in non-exposed group)
46
Q

What type of study is the risk ratio associated with? What type of study is the odds ratio associated with?

A
  • risk ratio - cohort study

- odds ratio - case-control study

47
Q

What are the advantages of a cohort study?

A
  • temporal sequence between exposure and disease established
  • assessing the effects of rare exposures
  • adequate numbers of exposed and nonexposed individuals identified
  • allows for examination of multiple effects of a single exposure
  • minimize potential for selection bias
48
Q

What are the disadvantages of a cohort study?

A
  • follow-up for many years
  • time-consuming
  • expensive
  • bias associated with loss to follow-up
49
Q

What is a retrospective cohort study?

A

exposure and outcome/disease have already happened at the start of the study

50
Q

What is the difference between cohort and case-control studies?

A
  • cohort - select individuals based on exposure and studying disease
  • case-control - select individuals based on disease and studying exposure
  • *these are my own definitions
51
Q

What does an analysis of variance (ANOVA) tell us?

A

whether the variance is due to treatment effects or due to error

52
Q

When completing an ANOVA table, how is the df for treatment found?

A

(# of groups) - 1

53
Q

When completing an ANOVA table, how is the SS (sums of squares) for treatment found?

A

SStx = SUM(n(groupmean - grandmean)^2)

n = number of samples in each group
grandmean = mean of all groups combined
54
Q

When completing an ANOVA table, how is the df for error found?

A

(total number of samples) - (number of groups)

55
Q

When completing an ANOVA table, how is the MS for treatment or error found?

A

MS = SS/df

56
Q

When completing an ANOVA table, how is the F ratio found?

A

F = MStx/MSerr

57
Q

What does the F ratio represent?

A

the probability that the variance between the groups is due to a difference between the groups is times greater than the variance being due to error

58
Q

What are the assumptions made during a ANOVA test?

A
  • interval/ratio (continuous) measurement scales
  • populations follow a normal distribution
  • populations have equal variance
  • independent groups
59
Q

What are 2 tests for unplanned comparisons?

A
  • Tukey test

- Dunnett’s

60
Q

If the independent variable is nominal/ordinal and the dependent variable is nominal/ordinal, what type of test is performed?

A

chi square

61
Q

If the independent variable is nominal/ordinal and the dependent variable is continuous, what type of test is performed?

A

t-test or ANOVA

62
Q

If the independent variable is continuous and the dependent variable is continuous, what type of test is performed?

A

correlation and regression

63
Q

What is the nonparametric equivalent to a linear regression and correlation?

A

chi square

64
Q

What is the nonparametric equivalent to a two-sample t-test?

A

Wilcoxon Rank Sums test

65
Q

What is the nonparametric equivalent to an ANOVA?

A

Kruskal-Wallis test

66
Q

What are the nonparametric equivalent to one-sample t-test?

A
  • Wilcoxon Sign Rank test

- McNemar test

67
Q

How does a Wilcoxon Rank Sums test work? Explain it.

A
  • arrange all of the data in ascending order
  • give a rank so that the smallest number is ranked 1 and so on
  • now categorize the data by its nominal group and sum up the ranks of the data in those groups so that each group has a rank sum
  • if the null hypothesis is true, each group should have the same rank sum
68
Q

What is the Kruskal-Wallis test used for?

A
  • extension of the Wilcoxon Rank Sum test
  • with two groups, it is like the t-test and ANOVA
  • can handle more than two groups
69
Q

How does the Wilcoxon Sign Rank test work? Explain it.

A
  • handles repeated measures
  • take the difference between the repeated measures and place it in order of smallest to biggest difference
  • assign each difference a rank
  • assign each difference a sign based on whether the difference is +/-
  • if the null hypothesis is true, the average for the + and the - ranks should be the same
70
Q

What type of information is more important in a McNemar test: when the two outcomes have the same result or when they differ?

A

when they differ because that refutes the null hypothesis

71
Q

What is the purpose of a diagnostic test?

A

diagnostic tests indicate the presence or absence of a disease and are usually compared to a “gold standard”

72
Q

What is the difference between sensitivity and specificity?

A
  • sensitivity - proportion with true disease that is diagnosed as having disease (TP/(TP+FN))
  • specificity - ability of test to correctly identify those without disease (TN/(TN+FP))
73
Q

Which (specificity or sensitivity) rules out the presence of disease? Which rules in the presence of disease?

A
  • specificity rules in the presence of disease

- sensitivity rules out the presence of disease

74
Q

What is the trade-off between sensitivity and specificity?

A

need both to be high, but usually one is increased at the expense of the other

AU13 - Evaluative Final (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions