DBS Exam D1

What value range will the Spearman rank correlation coefficient ρ (rho) always fall in? 0 to 1 -1 to 1 -1 to 0 0 to 5 -2 to 2

-1 to 1

3. Which of the following indicates a strong correlation? (Multiple answers) .97 -.36 .25 0 -.91

.97 and -.91

Which of the following best defines a systematic review? A process that scans many articles for data which fit the intent of the study A primary study A study that looks at a specific population at a specific point in time A review where one individual systematically gives a review of the topic at hand, usually with research to back it up A review that looks at a group of people defined by the presence or absence of a specific trait through time

A process that scans many articles for data which fit the intent of the study Explanation: A is the correct answer. B is the data that makes up a systematic review. C is a cross-sectional study. D is referring to editorials, opinions, and ideas. E is a cohort study

Conducting experiments on collected tissue is an example of what kind of study? A) In vitro B) In vivo C) Case report D) Cohort study E) Case-control study

A) In vitro Explanation: In vitro studies can be used to explore biological functions while isolated from biological context, while in vivo takes place in a living organism

In our example study design (randomized control trial, double blind), patients were placed in two groups, receiving either fluoride or no treatment. What kind of randomized controlled trial does this fall under? A. Parallel-Group B. Crossover C. Cluster D. Factorial E. Triple RCT

A. Parallel-Group Explanation: Parallel-group is correct because the groups received only one treatment each (not crossover or Factorial) and were not pre-selected (not cluster); Triple RCT is made up

How many sample observations are required in order to use the goodness of fit (Chi squared) test? 10 1 5 15

Answer: (5) Explanation: The sample observations must have at least 5 expected values in order to use this test. A randomization test will need to be performed if the expected values are less than 5.

. What are the types of Chi square tests? A - Goodness of fitIndependence test B - Dependence test C - All of the above D - A and B only

Answer: A and B only Explanation: there are only two types.

2. What is not a part of a Chi square test approach? State hypotheses Interpret results Analyze data Formulate analysis plan All of the above

Answer: all of the above Explanation: all of these are part of the approach.

In a graphical representation, an r value of -.61 will determine a. the slope of the line of best fit b. The direction of the line of best fit c. The strength of the correlation d. B and C e. All of the above

B and C

Which of these is NOT required for an in vitro study? A) Sample preparation and handling B) Patient consent *he said some need consent C) Isolated environment to perform tests D) Sufficient annotation of the array E) Statistical analysis

B) Patient consent *he said some need consent Explanation: In vitro studies does not require human participation

What does double blind mean? A. Participants and experimenters know who is receiving the specific treatments B. Neither participants nor experimenters know who is receiving the specific treatments C. Only experimenters know who is receiving the specific treatments D. Only participants know who is receiving the specific treatments E. The specific treatment itself is unknown

B. Neither participants nor experimenters know who is receiving the specific treatments

The Paired T-test has two competing hypotheses, the null and alternative hypothesis. With that being said, what does the null hypothesis assume in comparison to the alternative hypothesis? A. The null hypothesis assumes that the true mean difference between the paired samples is not equal to zero. While the alternative hypothesis assumes that the true mean difference between the paired samples is zero. B. The null hypothesis assumes that the true mean difference between the paired samples is zero. While the alternative hypothesis assumes that the true mean difference between the paired samples is not equal to zero. C. The null hypothesis assumes that the true mean difference between the paired samples is greater than zero. While the alternative hypothesis assumes that the true mean difference between the paired samples is less than zero. D. The null hypothesis assumes that the true mean difference between the paired samples is less than zero. While the alternative hypothesis assumes that the true mean difference between the paired samples is greater than zero. E. None of the above

B. The null hypothesis assumes that the true mean difference between the paired samples is zero. While the alternative hypothesis assumes that the true mean difference between the paired samples is not equal to zero.

Strengths of meta-analyses include all of the following except: Considered reliable and accurate Establish statistical significance across studies that might otherwise seem to have conflicting results Provide an overview of multiple studies Can be difficult, time-consuming, and include publication bias They enable generalization of results to a larger population

Can be difficult, time-consuming, and include publication bias Answer: D. These are weaknesses of a meta-analysis. Meta-analyses are time consuming and require synthesis of a large amount of data. Also, publication bias may be present in meta-analyses because a study is more likely to be published if the results are significant. All other choices are considered strengths

Which of the following is not needed to have an effective RCT design? A. PICOT format for hypothesis B. A well defined and approved protocol C. Random allocation of subjects D. The study must be double-blind E. All of the above are necessary

D. The study must be double-blind Explanation: The study does not have to be double blind to be effective. In many situations, it is impossible to have a double blind RCT (physical therapy trials)

What is the first step taken when performing a systematic review? Conduct a literature search for important resources Grab a coffee with your fellow scientists Analyze the level of bias Set inclusion and exclusion standards Define a clear research question and method

Define a clear research question and method Explanation: E is the first step in any good scientific process- ask a question, and define the steps you wish to take to reach an answer. If it's early, a coffee wouldn't be too bad either!!

Which study design should be used when one wants to describe a population, situation, phenomenon? Descriptive Study Experimental Study Cross-sectional Study Meta-Analysis Case Control Study

Descriptive Study Explanation: Descriptive studies describe a population, situation, or phenomenon that is being studied. Experimental studies measure the effect of independent variables on dependent variables.Cross-sectional studies analyze data from a population or representative subset at a specific point in time. Meta-analysis combines the results of multiple scientific studies. Case control studies are observational studies in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute

Which study design has only uncontrolled variables? Experimental Study Cohort Study Descriptive Study Meta-Analysis Case Control Study

Descriptive Study Explanation: Descriptive studies only contain uncontrolled variables. Experimental, Meta-Analysis, Cohort, and Case Control studies all contain independent and dependent variables

Cross-sectional study uses data that ____? Does not include manipulating variables Does not have any bias Are collected from multiple points in time Follows one group of participant Are hard and difficult to obtain

Does not include manipulating variables Explanation: A is the right answer. Variables can not be manipulated when data is taken. Data collected can be biased, collected from a single point in time, and does NOT have to follow a group. This study is actually easy and quick to do

Case studies attempt to demonstrate an association between _________ and _________ Disease; population Exposure; outcome Sensitivity; specificity Frequency ; time None of the above

Exposure; outcome

What level of information is in a Randomized Control Trial (single blind)? Level I Level II Level III Level IV Level V

Level II Single blind RCT provides a level II piece of evidence

Limitations of cross-sectional study includes which of the following? Must be performed before a cohort study Must collect data from multiple points in time Cannot compare groups across defined variables May have bias' including non-response, and prevalence bias Able to measure prevalence for all factors

May have bias' including non-response, and prevalence bias Explanation: D is the right answer. Cross-section study may have many bias' such as non-response, recall, or prevalence-incidence bias. This study does NOT have to be performed before a cohort study, collects data from a SINGLE point in time, and CAN compare groups across defined variables. E is not a limitation but an advantage

According to the hierarchy of scientific evidence, what studies provide the highest quality of evidence? Case control Randomized controlled trials Cohort studies Case reports Meta-analyses and systematic reviews

Meta-analyses and systematic reviews Answer: E. Systematic reviews and meta-analyses are considered to be the highest quality evidence on a research topic because their study design reduces bias and produces more reliable findings.

Can a cross-sectional study determine etiology? Yes, because cross-section study gathers data before and after incidence No, because cross-section study gathers at a single point in time Yes, because cross-section study has no data bias No, because cross-section study are relatively easy and quick to do Yes, because cross-section studies are a figment of our imagination

No, because cross-section study gathers at a single point in time Explanation: B is the right answer. Etiology is the cause of a disease or condition, cause and effect cannot be determined by a snapshot. Cross-section study does not gather data before or after, and has data bias. The study is easy and quick to do but has little relevance to etiology. B is the best answer

Cross-section studies are often used to determine what? Prevalence Incidence Causation Timeline of disease Rare diseases

Prevalence Explanation: A is the right answer. Prevalence is the proportion of people in a population who have a particular disease at a given time without taking into account when they developed this disease. Incidence is the rate at which NEW diseases are appearing. Causation is similar to etiology which cannot be determined because the data taken is of a single point in time. Rare diseases are hard to study because of small population size

What data is NOT needed for a Randomized Control Trial (single blind)? Randomly assigned groups Qualitative data that describes the investigator's purpose Data that describes the result of the control group Data that describes the result of the experimental or treatment group b and d

Qualitative data that describes the investigator's purpose RCT requires quantitative data

What is a disadvantage of case control studies? Large sample size required Discontinuous data Recall bias Simultaneously looks at multiple risk factors More time needed

Recall bias

Another name for "case control studies" is __________ Retrospective study Cohort study Cross-sectional study Longitudinal study Meta-analysis

Retrospective study

The Cohort study allow us to calculate all of the following, except one incidence rate Cumulative Incidence Rate Secondary Attack Rate relative risk, hazard ratio

Secondary Attack Rate

The Wilcoxon signed-rank test makes use of the magnitude of the difference between paired observations but the Sign test uses only the direction of the difference Kruskal-Wallis uses the sign of the difference Sign test uses the square of the difference Sign test uses the residuals Wilcoxon test uses only the square of the difference

Sign test uses only the direction of the difference

What does the one sample median test attempt to measure/show? An exact test of statistical significance of any deviation from what is expected in the distribution of observations in two particular categories To show if two groups from the same population are the same or different in some way Used to detect differences in treatments across multiple test attempts after ranking each block or row Significant difference between our hypothesized median and the real median of a sample Attempts to draw a line of best fit through the data of two variables and the pearson's correlation

Significant difference between our hypothesized median and the real median of a sample

In which type of randomization can groups be unequally sized? Stratified Simple Block Complex a and b

Simple In stratified and block RCT, groups are equally sized

Which of the following is NOT true regarding animal research studies? Animal research studies have led to the development of human vaccines A researcher must first obtain a license before conducting animal research Animal research studies have led to development of animal vaccines Test animals are typically gathered from shelters & animal rescues There is an ethical debate regarding whether or not animals should be tested on

Test animals are typically gathered from shelters & animal rescues Explanation: Animals are typically bred in the lab specifically for use in research. They are not usually taken from shelters or rescues

Which of the following is not a requirement of the one sample t-test? Data must be normally distributed Test variable must be discrete Data must be a random sample of the population Data must have homogeneity of variance There must be no outliers in the data set

Test variable must be discrete

When utilizing a binomial tests, which of the following is NOT an assumption? Items are binary, meaning there are two of them and they are nominal The sample item is dependent, meaning one item has bearing on the other The same sample size is significantly less than the population size The sample is a fair representation of the population The sample items are independent, meaning one item has no bearing on the other

The sample item is dependent, meaning one item has bearing on the other

Which of the following is not needed for a Pearson Correlation? A random sample Each of the data points has both variables (X and Y) There must be at least one outlier in the data set There is a linear association All of the above are needed for the Pearson Correlation

There must be at least one outlier in the data set

Which is not a limitation of the cohort study? You may have to follow large numbers of subjects They are not good for very rare diseases. They are not good for diseases with a long latency They are low cost and have a quick turnaround time Differential losses to follow up can occur, which creates bias

They are low cost and have a quick turnaround time

What was the cohort study originally designed for? To describe a study that compared the disease experience of people born at different periods To closely examine a specific person's disease experience To look forward at the future risk experience of a specific group To determine the likelihood of disease spreading between populations Eliminate bias

To describe a study that compared the disease experience of people born at different periods

2. The sign test and the Wilcoxon signed-rank test both Assume normal populations. Assume independent samples. Use the nominal scale of measurement. Assume grouped samples. Uses square of the difference.

Use the nominal scale of measurement.

What type of questions are descriptive studies unable to answer? Who What Where Why How

Why Explanation: Descriptive studies do not answer the why of a research problem as one needs to have thorough understanding of a research problem before ascertaining why the problem exists

Do animal research studies help animals? No, animal research studies only benefits humans Yes, animal research studies have allowed for medications, treatments, etc. for the animal kingdom to become much more vast No, animal research studies are abusive towards animals. Yes, animal research studies help animals by giving them a purpose in life No, animal researches studies have little benefit to humans and or animals and should be considered an outdated study method

Yes, animal research studies have allowed for medications, treatments, etc. for the animal kingdom to become much more vast Explanation: Although we gain much benefit from animal research as humans, many of the drugs tested on animals have shown to help them just as effectively if not more so than what it was intended for for humans. It also allowed us to gain a much better understanding of animal anatomy, physiology, and psychology

A meta-analysis is described as study design that randomly assigns participants into an experimental group or a control group quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute type of observational study that analyzes data from a population, or a representative subset, at a specific point in time retrospective study that looks back in time to find the relative risk between a specific exposure (e.g. second hand tobacco smoke) and an outcome (e.g. cancer)

a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research Answer: B. This is the definition of a meta-analysis study

Which of the following is/are a limitation of the Paired T-test? a. The difference for the matched pairs, must follow a normal probability distribution b. The sample of pairs cannot be a random sample from the population c. The data is discontinuous d. All of the above e. None of the above

a. The difference for the matched pairs, must follow a normal probability distribution

The WMW Test uses which type of data? a. ordinal b. interval c. ratio d. nominal

a. ordinal

The Friedman's Test uses what sampling method? a. Random sample b. Systematic sample c. Stratified d. Cluster sample e. Non-random sample

a. random sample

The Friedman's Test uses what information to find differences in treatments? a. Rank (ranked retrieval) b. Set (set retrieval) c.Discrete d. Non-random e. Non-continuous

a. rank (ranked retrieval)

The WMW Test must use this data for calculations because the data can be ____? a. ranked b. normalized c. paired d. easily probed for period pocket depth

a. ranked

What is/are the limitations of case reports and series a)Lacks clinical presentation b)Lacks a comparison or control group c)The evidence is anecdotal based d)None of the above e)All of the above

b)Lacks a comparison or control group Explanation: Case report and series lack a comparison or control group to compare outcomes and have little statistical validity. It cannot compare what is happening with others who do not have the condition or treatment

How many factors can the Friedman's Test analyze? a. 0 b. 1 c. 2 d. > or equal to 3 e. no greater than 5

b. 1

Fisher's exact test is a statistical test used to determine if there are _____ associations between ______ categorical variables. A. Random, three b. Nonrandom, two c. Random, two d. Nonrandom, four e. Random, four

b. Nonrandom, two

If conditions for a Wilcoxon-Mann-Whitney test are met AND the data is normally distributed, which test should you use instead? a. Chi-Squared b. T-Test c. Binomial Test d. The Statistics test

b. T-Test

Choose the best study design to use One-Way ANOVA: a. In a group of randomly picked people, which have composite restorations vs. amalgam restorations. b. Testing to see the difference in monomer release from 3 different composite resins. c. Determine if the risk assessment for caries differ between family members. d. Comparing if full mouth crowns are significantly better than complete dentures.

b. Testing to see the difference in monomer release from 3 different composite resins.

the Wilcoxon-Mann-Whitney test compares the ____ between two independent sets of data? a. Median b. Mean c. Bounds d. Shape

b. mean

Analogous to the chi-square test, Fisher's exact test is a nonparametric test for categorical data, but can be used in situations in which the chi-square test cannot, such as with _____________________. a. large sample sizes b. small sample sizes c. data sets with a high average d. data sets with a low average e. data sets with no outliers

b. small sample sizes

What is the data collected in a one sample T-test ultimately compared to? Margin of error Standard value Second group in the study Critical-value chart ANOVA Test

b. standard value

Which of the following statements is correct about test tubes? a) Test tubes are used to measure solutions b) Test tubes are used to measure liquids c) Test tubes are used for qualitative observations, but not for measuring solutions and liquids d) Test tubes are used for quantitative observations, but not for measuring solutions and liquids e) Test tubes are used for very large scale experiments and reactions

c) Test tubes are used for qualitative observations, but not for measuring solutions and liquids Explanation: Test tubes are widely used by researchers to handle chemicals, especially for qualitative experiments and assays. Their spherical bottom and vertical sides reduce mass loss when pouring, make them easier to wash out, and allow convenient monitoring of the contents

What kind of data do editorial study designs need? a) quantitative b) experimental c) qualitative and quantitative d) survey / interview e) qualitative

c) qualitative and quantitative Quantitative research deals with numbers and statistics, while qualitative research deals with words and meanings - and editorial deals with both. Editorials attempt to formulate viewpoints based on a subjective analysis of what is happening and conflicting/contrary opinions

An editorial discusses which of the following? a) published research published over 10 years ago b) meta-analysis reviews only c) subjective research topic of interest d) objective opinions only e) news only

c) subjective research topic of interest Remember that editorials are known specifically for being subjective. It is an individual's opinion on a current event or social issue. The goal of a good editorial is to persuade the reader to consider your perspective and change their opinion

Which of the following conditions about case reports and series is true? a)Case report and series is always retrospective B)Case report and series involve hypothesis testing c)For all case reports and case series a HIPAA authorization should be obtained d)Case report and series are comparative and have a large number of individuals e)When there is more than two patients a submission to the designated IRB is required

c)For all case reports and case series a HIPAA authorization should be obtained Explanation: A HIPPA form is required from the parent or legally authorized representative for use and disclosure of their protected health information. De-identifying case reports will not need a HIPAA authorization

True or False: The Kruskal-Wallis Test does assume normality in data and is much less sensitive to outliers a. Both Statements are True b. The first statement is true and the second is false c. The first statement is false and the second statement is true d. Both statements are false

c. The first statement is false and the second statement is true

1. The Paired T-test, also called the dependent T-test, is a statistical procedure used to measure/determine ____________. a. Whether the mean difference between two sets of observations is one. b. Whether the mean difference between two sets of observations is two. c. Whether the mean difference between two sets of observations is zero. d. Whether the mean difference between two sets of observations is not zero. e. None of the above

c. Whether the mean difference between two sets of observations is zero.

In a One-Way ANOVA, the dependent variable is ______ and the independent variable is ______. a. Nominal; Interval b. Ordinal; Ratio c. Ratio; Nominal d. Nominal; Ordinal

c. ratio; nominal

The probability of rejecting the null hypothesis when it is in fact correct is known as what? Degrees of Freedom Standard Value Significance Level Mean Value Median Value

c. significance level

Which of the following is not a limitation in Ideas, Editorials, Opinions? a) controversy is difficult to avoid b) prone to bias and errors of reasoning c) experts at the bottom level of evidence quality d) a highly credible source e) least reliable source

d) a highly credible source Editorials are one of the least credible sources, prone to controversy, bias, errors, and are at the bottom of the food chain in terms of respectable in the field of publishing

You have designed a study where people either say that they like the Oral-B electric toothbrush or they do not. What type of distribution would you use? a. normal distribution b. non-normal distribution c. noncentral t-distribution d. binomial distribution e. central distribution

d. binomial distribution

Fisher's exact test assumes that the individual observations in a given test are _____ and the row and column totals are ________. a. interdependent , flexible b. independent, flexible c. dependent, fixed d. independent, fixed e. interdependent, fixed

d. independent, fixed

The null hypothesis in a fisher exact test says that rows and columns are: a. Are associated b. the same c. not the same d. not associated e. inversely associated

d. not associated

Fisher's (exact) test is practically applied in analysis of _________ samples; however, it is actually valid for _________ sample sizes. a. all, only small b. all, only large c. all, no d. only small, all e. only large, all

d. only small, all

Which of the following data does case reports and series not use? a)Case series b)Quantitative data c)Archival data d)Patient data e)Case reports and series use all of the data above

e)Case reports and series use all of the data above Explanation: The data used for case reports and series are case data, patient data, quantitative data, field notes and research observations, data about explanations and studies that rival the case study reports, archival data, time period over which study was conducted, and case series

Analysis of Variance (One-way ANOVA) is a statistical method of comparing the _______ of several populations. a. Variance b. Standard deviation c. Proportion d. Means e. None of the above

e. means

A Cohort Study: A clearly defined

group of persons who are studied over a period of time to determine the incidence of death, disease, or injury

What type of correlation would one have in a Spearman Correlation test if one variable decreases as the other variable increases? Positive Correlation Negative Correlation Zero Correlation Pearson Correlation Spearman Correlation

negative correlation

A case-control study is a type of ________________ study because _________________________________________________________

observational study because no attempt or intervention is made to change the course of the disease

The binomial distribution depends on which of the following? Mean and standard deviation Standard deviation and number of successes Sample size and probability of success Mean and probability of success Both C & D

same size and probability of success

Which statistical test determines the strength and direction of the monotonic relationship between two variables? Pearson Correlation Spearman Correlation Binomial Test Chi-Square Test One way anova

spearmen correlation

Which of the following studies would NOT be useful to a systematic review? study found in a public access journal with easy to reference materials study with clear cut explanations for data gathering procedures. study published in a journal with a subscription fee study without references published outside of an official scientific journal study based on clinical results and examination from a rural area of the country

study without references published outside of an official scientific journal Explanation: In this scenario, the answer would be D. A, B, and E are all examples of good studies to use for a systematic review. C seems tricky, as it is a bit harder to access due to the subscription fee- however, journals with subscription fees tend to publish good research. D is the best choice for this question, as a study without references and published outside of a trusted method is not a great option for a systematic review