DBS Final Exam
True or False: The Paired T-test is used to compare unpaired variables, but not for data involving more than two groups.
Answer: False — The Paired T-test is used to compare paired variables only.
2. Which of these is NOT required for an in vitro study? A) Sample preparation and handling B) Patient consent C) Isolated environment to perform tests D) Sufficient annotation of the array E) Statistical analysis
B) Patient consent
In which type of randomization can groups be unequally sized? A) Stratified B) Simple C) Block D) Complex E) a and b
B) Simple
What is a disadvantage of case control studies? A) Large sample size required B) Discontinuous data C) Recall bias D) Simultaneously looks at multiple risk factors E) More time needed
C) Recall bias
1. Which is not a favorable condition to use the binomial test? A. There are two possible outcomes. B. Each outcome is dependent on the next. C. The sample size is less than the population size. D. Each outcome is independent of the next. E. The null hypothesis is that two outcomes are equally likely to occur.
: B — Each outcome is independent and has no bearing on the
Select the incorrect statement: a) The Wilcoxan Mann-Whitney test generally compares two data sets b) The Wilcoxan Mann-Whitney test places data in ascending order c) The Wilcoxan Mann-Whitney test usually compares the mode of the data sets d) The Wilcoxan Mann-Whitney test often serves as an alternative to the two sample t-test
: C — Explanation: The Mann-Whitney test usually compares the MEDIAN and sometimes the MEAN, but never the mode.
All of the following are assumptions of the Wilcoxon-Mann-Whitney test except which one? a) One dependent variable should be measured at the ordinal or continuous level b) One independent variable should consist of two categorical, independent groups c) There is independence of observations d) Distribution of scores are normally distributed
: D — Explanation: The distribution of scores for both groups of the independent variable are not normally distributed - but they should follow the same shape in order to determine if there are any differences in the medians of the two groups
1. When should the Fisher Test be used over the Chi Square Test? A. Sample size is small and a cell's value <5 B. When working with ordinal data C. Sample size is large and accuracy is important D. A and B
A is correct. If the sample size is greater than 20 or an individual cell's value exceeds
If the Pearson Product Moment Correlation Coefficient shows zero value, this means that a. there is no linear correlation b. total positive linear correlation c. total negative linear correlation d. There is no relationship
A — If we get a low value or 0 value, it means that there is no linear correlation. It doesn't mean there is no relationship.
. A One Sample T-Test compares _______________ to determine whether there is a significant difference. a) A sample mean and a population mean b) Two sample means c) Two population means d) Two or more e) None of the above
A — Since the standard deviation is unknown, the significant difference is determined by comparing the sample mean and the population mean.
Which of the following indicates a strong correlation? (Multiple answers) A) .97 B) -.36 C) .25 D) 0 E) -.91
A) .97 E) -.91
Which of the following best defines a systematic review? A) A process that scans many articles for data which fit the intent of the study. B) A primary study. C) A study that looks at a specific population at a specific point in time. D) A review where one individual systematically gives a review of the topic at hand, usually with research to back it up. E) A review that looks at a group of people defined by the presence or absence of a specific trait through time.
A) A process that scans many articles for data which fit the intent of the study.
True or False: omnibus test statistic and cannot tell you which specific groups of your independent variable are statistically significantly different from each other 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
A) Both Statements are True
Which study design should be used when one wants to describe a population, situation, phenomenon? A) Descriptive Study B) Experimental Study C) Cross-sectional Study D) Meta-Analysis E) Case Control Study
A) Descriptive Study
Cross-sectional study uses data that ____? A) Does not include manipulating variables. B) Does not have any bias. C) Are collected from multiple points in time. D) Follows one group of participant. E) Are hard and difficult to obtain.
A) Does not include manipulating variables.
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
The WMW Test uses which type of data? A) Ordinal B) Interval C) Ratio D) Nominal
A) Ordinal it is actually ordinal and continuous
In our example study design, 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
Cross-section studies are often used to determine what? A) Prevalence B) Incidence C) Causation D) Timeline of disease E) Rare diseases
A) Prevalence
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 periodontal pocket depth
A) Ranked
Another name for "case control studies" is __________. A) Retrospective study B) Cohort study C) Cross-sectional study D) Longitudinal study E) Meta-analysis
A) Retrospective study
The Wilcoxon signed-rank test makes use of the magnitude of the difference between paired observations but the A) Sign test uses only the direction of the difference. B) Kruskal-Wallis uses the sign of the difference. C) Sign test uses the square of the difference. D) Sign test uses the residuals. E) Wilcoxon test uses only the square of the difference.
A) Sign test uses only the direction of the difference.
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 (note, the data is continuous aka is a number)
What was the cohort study originally designed for? A) To describe a study that compared the disease experience of people born at different periods B) To closely examine a specific person's disease experience C) To look forward at the future risk experience of a specific group D) To determine the likelihood of disease spreading between populations E) Eliminate bias
A) To describe a study that compared the disease experience of people born at different periods
Who are the creators of the Wallis Test? A) Wilson A. Wallis & William H Kruskal B) William A. Wallis & Wilson H. Kruskal C) James A. Wallis & Harry H. Kruskal D) Nader F. Abdulhameed & Hind S. Hussein
A) Wilson A. Wallis & William H Kruskal
When is the null hypothesis rejected in a Kruskal Wallis test? a. If the calculated value is less than the chi-square critical value b. If the calculated value is greater than 1 c. If the calculated value is larger than the chi-square critical value d. If the calculated value is less than 1 e. You are unable to reject the null hypothesis with a Kruskal Wallis test
Answer A, you would be unable to reject the null hypothesis. Answers B and D are incorrect because it would depend on the chi-square critical value as to whether less than 1 or greater than 1 is correct. Answer E is incorrect because you can reject a null hypothesis if the calculated value is larger than the chi-square critical value.
. Which of the following is a characteristic of a Kruskal Wallis test? a. Use of ranks instead of actual data in calculations b. It is a normal distribution (parametric test) c. Used to compare the means of groups of measured data d. It has 5 key steps to completing the test e. It does not use chi-square distribution
Answer: A — The KWT takes data and ranks that data and then uses the ranked order for calculations. B and C are characteristics of a one-way ANOVA test. The KWT uses 7 steps and it does use chi-square distribution. Kruskal- wallis tests compare the medians of groups.
If a chi-squared test was performed and the P-value was 0.4, what would that mean? A. We would fail to reject the null hypothesis B. We would accept the alternative hypothesis C. We would accept neither hypothesis D. We accept both hypothesis E. We would reject the null hypothesis
Answer: A — the P-value obtained is greater than 0.05 meaning we fail to reject the null and cannot prove the alternative.
When doing statistical analysis using a One-way ANOVA, how many factors can the data be categorized with? A. One B. Two C. Three D. Less than three E. More than three
Answer: A. One-way ANOVA can only be used with data concerning one independent variable. If you need to analyze data that is categorized with 2 factors you would need to use the two-way anova method.
All of the following are limitations/assumptions of the Paired T-test except.... A. Continuous data B. No outliers C. Discrete Data D. Matched pairs E. Normally distributed
Answer: C — Discrete data can not be used, data must be continuous and numerical. Tiime, weight, or test scores.
The paired t-test requires data that is numeric and continuous. Which of the following are examples of continuous data? A. Interval/ratio B. Height C. Low-high D. Age E. a, b, d F. c, d
Answer: E — Continuous data can take any value in a range or interval/ratio (height, age) vs. discrete data which can only take on a few values such as low, medium, and high.
. How many populations are needed for a One-Way ANOVA? A. One B. Two C. Three D. Two or more E. Three or more
Answer: E. The test requires three or more populations in order to get a good comparison.
The Wilcoxon signed-rank test makes use of the magnitude of the difference between paired observations but the A. Sign test uses only the direction of the difference. B. Kruskal-Wallis uses the sign of the difference. C. Sign test uses the square of the difference. D. Sign test uses the residuals. Wilcoxon test uses only the square of the difference
B Explanation: The sign test works only on the difference between related observations, but the Wilcoxon signed-rank test takes into account the magnitude of the differences.)
A botanist wants to know if taller sunflower plants have wider stems. She measures and ranks the heights and widths of several plants and calculates a Spearman's rank correlation coefficient (rs) of 0.857. What does this data indicate? A. Inconclusive, you would need a significance test B. Taller sunflowers are positively correlated with wider stems C. Taller sunflowers are positively correlated with skinnier stems D. Taller sunflowers are negatively correlated with wider stems E. There is no correlation between the height and width of sunflower stems
B — Explanation: The closer the coefficient value is to 1, the stronger the correlation is going to be. A positive value indicates a positive correlation, i.e. both variables increase together
Which of the following indicates the strongest spearman correlation (rs) value? A. 0.85 B. -0.89 C. 0.37 D. 2 E. -0.64 B — Values closer to ±1 indicate a stronger relationship while the sign indicates the direction.
B — Values closer to ±1 indicate a stronger relationship while the sign indicates the direction
What value range will the Spearman rank correlation coefficient ρ (rho) always fall in? A) 0 to 1 B) -1 to 1 C) -1 to 0 D) 0 to 5 E) -2 to 2
B) -1 to 1
How many factors can the Friedman's Test analyze? A) 0 B) 1 C) 2 D) ≥3 E) No greater than 5
B) 1
Case studies attempt to demonstrate an association between _________ and _________. A) Disease; population B) Exposure; outcome C) Sensitivity; specificity D) Frequency ; time E) None of the above
B) Exposure; outcome
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
What level of information is in a Randomized Control Trial (single blind)? A) Level I B) Level II C) Level III D) Level IV E) Level V
B) Level II
What type of correlation would one have in a Spearman Correlation test if one variable decreases as the other variable increases? A) Positive Correlation B) Negative Correlation C) Zero Correlation D) Pearson Correlation E) Spearman Correlation
B) Negative Correlation
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
Can a cross-sectional study determine etiology? A) Yes, because cross-section study gathers data before and after incidence B) No, because cross-section study gathers at a single point in time C) Yes, because cross-section study has no data bias D) No, because cross-section study are relatively easy and quick to do E) Yes, because cross-section studies are a figment of our imagination
B) No, because cross-section study gathers at a single point in time
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 (trying to prove null wrong so we can prove it's non random. We are looking if the variation is due to chance or not)
What data is NOT needed for a Randomized Control Trial (single blind)? A) Randomly assigned groups B) Qualitative data that describes the investigator's purpose C) Data that describes the result of the control group D) Data that describes the result of the experimental or treatment group E) b and d
B) Qualitative data that describes the investigator's purpose
Which statistical test determines the strength and direction of the monotonic relationship between two variables? A) Pearson Correlation B) Spearman Correlation C) Binomial Test D) Chi-Square Test E) One way anova
B) Spearman Correlation
What is the data collected in a one sample T-test ultimately compared to? A) Margin of error B) Standard value C) Second group in the study D) Critical-value chart E) ANOVA Test
B) Standard value (standard value is basically the number of standard deviations away from the mean of the population i think)
Which of the following is not a requirement of the one sample t-test? A) Data must be normally distributed B) Test variable must be discrete C) Data must be a random sample of the population D) Data must have homogeneity of variance E) There must be no outliers in the data set
B) Test variable must be discrete (discrete means numeric value between two values. an example is the number of complaints a customer makes or the number of flaws in a production line)
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 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.
I DONT LIKE THIS QUESTION When utilizing a binomial tests, which of the following is not an assumption? A) Items are binary, meaning there are two of them and they are nominal B) The sample item is dependent, meaning one item has bearing on the other C) The same sample size is significantly less than the population size D) The sample is a fair representation of the population E) The sample items are independent, meaning one item has no bearing on the other
B) The sample item is dependent, meaning one item has bearing on the other
Do animal research studies help animals? A) No, animal research studies only benefits humans B) Yes, animal research studies have allowed for medications, treatments, etc. for the animal kingdom to become much more vast. C) No, animal research studies are abusive towards animals. D) Yes, animal research studies help animals by giving them a purpose in life E) No, animal researches studies have little benefit to humans and or animals and should be considered an outdated study method.
B) Yes, animal research studies have allowed for medications, treatments, etc. for the animal kingdom to become much more vast.
A meta-analysis is described as: A) a study design that randomly assigns participants into an experimental group or a control group. B) a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research. C) a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. D) a type of observational study that analyzes data from a population, or a representative subset, at a specific point in time E) 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).
B) a quantitative, formal, epidemiological study design used to systematically assess previous research studies to derive conclusions about that body of research.
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) paired T-Test
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 averaged. data sets with a low average E) data sets with no outliers
B) small sample sizes (5 or fewer) (don't use fisher if more than 20)
. T
C Ex
2. Which of the following is NOT a main assumption for data in the One Sample T Test? a) Continuous dependent variable b) Independent observations c) Dependent observations d) Normally distributed dependent variable e) No outliers in the dependent variable
C - The observations should be independent of each other. This means that an observation should not alter or influence another observation.
3. Which of the following scenarios would be most appropriate for using Fisher's Test? A. You want to study the association between the number of hours spent studying and test scores among 19 college students. B. You want to determine the number of smokers or nonsmokers who develop cancer in a sample of 2,342 people. C. You want to investigate the number of patients are cured or ill after treatment with chloroquine or a placebo in a sample of 16 subjects. D. All of the above E. None of the above THEY'RE WRONG. YOU WOULD NEED CURED, ILL, IN REMISSION
C is correct. In this case, the data is nominal, with two variables (drug treatment or placebo), two potential outcomes (cured or ill), and a sufficiently small sample size to allow Fisher's test to be used. In answer A, although sample size is small, the data is ordinal, not nominal. In answer B, although the data is nominal, the sample size is too large.
By what alternative name is Pearson's Correlation Analysis also known a. Spearman's Correlation Analysis b. Chi-Squared Product- Moment c. Pearson's Product - Moment d. None of these
C — Also Known As: Pearson's r, Pearson product-moment correlation coefficient, Bivariate Correlation.
The Spearman Correlation constraint is between -1 ≤ rs ≤ 1, a value of zero (0) would signify what type of correlation? A. A strong positive monotonic correlation B. A strong negative monotonic correlation C. A non-monotonic correlation D. A weak negative monotonic correlation E. A weak positive monotonic correlation
C — Explanation: If spearman correlation coefficient of a variable is close to 0, it means there is no monotonic relationship between variables.
The Wilcoxon-Mann-Whitney Test is an analog to which of the following tests? a) Chi-square test b) One-Way ANOVA c) Independent T-test d) Kruskal Wallis Test I DONT LIKE THIS QUESTION
C — Explanation: The Mann-Whitney test is similar to the T-test. However, unlike the independent T-test which is used when the data is normally distributed, the Mann Whitney test is used when the sample data is not normally distributed.
Homoscedasticity can be checked using which type of graph? a. Bar chart b. Line graph c. Scatter plot d. Pie chart
C — Pearson Correlation Test data shows homoscedasticity shown in scatter plot graph
After performing a binomial test, the p value was .006. you would: A. Accept the null hypothesis. B. Reject the alternative hypothesis. C. Reject the null hypothesis. D. Confirm the test was inconclusive. E. Get a bigger sample size and perform the test again.
C — You would reject the null hypothesis. A p value less than .05 indicates a significant difference between the sample and given values.
How many sample observations are required in order to use the goodness of fit test? A) 10 B) 1 C) 5 D) 15
C) 5
Which study design has only uncontrolled variables? A) Experimental Study B) Cohort Study C) Descriptive Study D) Meta-Analysis E) Case Control Study
C) Descriptive Study
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
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 (all three groups have different blood types (nominal), so is there a difference in their body tempreatures? (ratio))
The binomial distribution depends on which of the following? A) Mean and standard deviation B) Standard deviation and number of successes C) Sample size and probability of success D) Mean and probability of success E) Both C & D
C) Sample size and probability of success
The Cohort study allow us to calculate all of the following, except one. A) incidence rate B) Cumulative Incidence Rate C) Secondary Attack Rate D) relative risk, E) hazard ratio
C) Secondary Attack Rate (relative risk: ratio of incidence rate of subjects to control subjects) (Hazard ratio:
The probability of rejecting the null hypothesis when it is in fact correct is known as what? A) Degrees of Freedom B) Standard Value C) Significance Level D) Mean Value E) Median Value
C) Significance Level
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.
True or False: The Kruskal-Wallis Test does assumes 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
What is a limitation of an Animal research study? A) Animals have too long of a lifespan to show any experimental data B) The variety of animals is too large and can interfere with data collection accuracy. C) There is often a discord between human diseases and animal diseases D) Animals do not have the same human awareness, so they cannot participate in experimental research as well as humans can. E) Animal research is very inexpensive.
C) There is often a discord between human diseases and animal diseases
Which of the following is not needed for a Pearson Correlation? A) A random sample B) Each of the data points has both variables (X and Y) C) There must be at least one outlier in the data set D) There is a linear association E) All of the above are needed for the Pearson Correlation
C) There must be at least one outlier in the data set
The sign test and the Wilcoxon signed-rank test both A) Assume normal populations. B) Assume independent samples. C) Use the nominal scale of measurement. D) Assume grouped samples. E) Uses square of the difference.
C) Use the nominal scale of measurement. ???????????????????????????????????????? can't you also say it assumes independent samples
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.
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
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 (Editorials = short essays to demosntrate views of an auther on topic of research)
Which of the following possible outcomes would not be indicative to use the binomial test? A. Cavities/No cavities B. Male/female C. Rolling a 2,3, or 4 D. Success/Failure E. Floss/Don't floss
C. There can only be two possible outcomes to use the binomial test. For more than two outcomes, a multinomial test would be indicated.
What does the one sample median test attempt to measure/show? A. An exact test of statistical significance of any deviation from what is expected in the distribution of observations in two particular categories B. To show if two groups from the same population are the same or different in some way C. Used to detect differences in treatments across multiple test attempts after ranking each block or row D. Significant difference between our hypothesized median and the real median of a sample E. Attempts to draw a line of best fit through the data of two variables and the pearson's correlation
D Explanation: Significant difference between our hypothesized median and the real median of a sample. Remember that the one sample median test is a non-parametric test testing non-metric values and cannot determine actual differences in a population)
Which of the following is NOT a stipulation of Fisher' Test? A. B. The data must be nominal C. The number of outcomes must be fixed D. There must be three or more variables E. All of the above are required
D is incorrect. It is possible to use Fisher's Test to study 3 variables, but it only requires a minimum of two. Commonly two variables and two categories are arranged in a 2 by 2 table.
Which of the following studies would NOT be useful to a systematic review? A) A study found in a public access journal with easy to reference materials. B) A study with clear cut explanations for data gathering procedures. C) A study published in a journal with a subscription fee. D) A study without references published outside of an official scientific journal. E) A study based on clinical results and examination from a rural area of the country.
D) A study without references published outside of an official scientific journal.
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
D) B and C (negative means line of best fit goes down. The lower the number to zero, the more scattered the data points)
Strengths of meta-analyses include all of the following except: A) Considered reliable and accurate B) Establish statistical significance across studies that might otherwise seem to have conflicting results C) Provide an overview of multiple studies D) Can be difficult, time-consuming, and include publication bias E) They enable generalization of results to a larger population
D) Can be difficult, time-consuming, and include publication bias
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
Limitations of cross-sectional study includes which of the following? A) Must be performed before a cohort study. B) Must collect data from multiple points in time. C) Cannot compare groups across defined variables. D) May have bias' including non-response, and prevalence bias. E) Able to measure prevalence for all factors.
D) May have bias' including non-response, and prevalence bias.
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
D) Means
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
What does the one sample median test attempt to measure/show? A) An exact test of statistical significance of any deviation from what is expected in the distribution of observations in two particular categories B) To show if two groups from the same population are the same or different in some way C) Used to detect differences in treatments across multiple test attempts after ranking each block or row D) Significant difference between our hypothesized median and the real median of a sample E) Attempts to draw a line of best fit through the data of two variables and the pearson's correlation
D) Significant difference between our hypothesized median and the real median of a sample
Which of the following is NOT true regarding animal research studies? A) Animal research studies have led to the development of human vaccines B) A researcher must first obtain a license before conducting animal research C) Animal research studies have led to development of animal vaccines D) Test animals are typically gathered from shelters & animal rescues E) There is an ethical debate regarding whether or not animals should be tested on
D) Test animals are typically gathered from shelters & animal rescues
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
Which is not a limitation of the cohort study? A) You may have to follow large numbers of subjects B) They are not good for very rare diseases. C) They are not good for diseases with a long latency. D) They are low cost and have a quick turnaround time E) Differential losses to follow up can occur, which creates bias
D) They are low cost and have a quick turnaround time
What type of questions are descriptive studies unable to answer? A) Who B) What C) Where D) Why E) How
D) Why
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
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) non-central t-distribution D) binomial distribution E) central distribution
D) binomial distribution
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 is false about the chi-squared test? A. The chi-square test is sensitive to sample size. B. The chi squared test does not give information about the strength of a relationship C. The chi-square test cannot establish a causal relationship between two variables. D. A small sample size is preferred (less than 5) E. Tests relationships between categorical variables
D. A small sample size is preferred (less than 5) — If the expected number of observations in any category is too small, the chi-square test may give inaccurate results
The best set of data that fits the requirements needed to run a Chi-Squared test would most likely be? A. Heights of men in Dental Schools B. Weights of Bowling Balls at your local bowling alley C. Pulpal Floor Depths made among first year dental students D. birthday month of each individual in dental school E. Grams of Epinephrine in one carpule of anesthetic
D. Gender of an individual in dental shcool The Chi-Squared test only works for categorical sets of data (ones with finite groupings)... the other answer choices are examples of numerical data.
What are the types of Chi square tests? A) Goodness of fit B) Independence test C) Dependence test D) All of the above E) A and B only
E) A and B only
What is not a part of a Chi square test approach? A) State hypotheses B) Interpret results C) Analyze data D) Formulate analysis plan E) All of the above
E) All of the above
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 (archival data is info that exists in someone else's files)
What is the first step taken when performing a systematic review? A) Conduct a literature search for important resources. B) Grab a coffee with your fellow scientists. C) Analyze the level of bias. D) Set inclusion and exclusion standards E) Define a clear research question and method.
E) Define a clear research question and method.
According to the hierarchy of scientific evidence, what studies provide the highest quality of evidence? A) Case control B) Randomized controlled trials C) Cohort studies D) Case reports E) Meta-analyses and systematic reviews
E) Meta-analyses and systematic reviews
The population mean and the sample mean are used to determine the unknown standard deviation in a One Sample T Test
T
All of the following are assumptions of the Kruskal Wallis test except one. Which is the exception? a. All groups have the same shape distributions b. One independent variable with two or more independent groups c. Observations should be independent d. All data follows a normal distribution e. Measurement scale is at least ordinal, it can be ranked
The KWT by definition is a non-parametric test in which the data will not follow a normal distribution. If data follows a normal distribution then a one-way ANOVA test can be used. KWT tests should have one independent variable that has at least two independent groups however, most of the time three is ideal.
Which of the following tests is a non-parametric alternative to the one-way ANOVA test? a. Mann-Whitney U Test b. Kruskal Wallis Test c. Chi-Square Test d. Fisher Test e. Freidman Test
The Kruskal Wallis Test is a non-parametric alternative to a one-way ANOVA test. 2. Which of the following is a characteristic of a Kruskal Wallis test?
Which of the following variables are involved in a Kruskal Wallis test? a. Ordinal variables b. Categorical variables c. Continuous variables d. All of the above e. None of the above
The Kruskal Wallis test is a rank-based nonparametric test that can be used to determine if there are statistically significant differences between two or more groups of an independent categorical variable on a continuous or ordinal dependent variable. Therefore, the KWT always uses a categorical variable and can be used for either continuous or ordinal variables.
If the calculated F-value in a One Way ANOVA test is greater than the F-critical value we...? A. Keep the null hypothesis B. Determine that our data is not statistically significant C. Reject the null hypothesis and accept the alternative hypothesis D. Have error in our data E. Reject both the null and alternative hypothesis
We will reject the null hypothesis and accept the alternative hypothesis. However, we cannot conclude from ANOVA that any particular mean is different from the others
What do you do to the values BELOW the hypothesized median for the One Sample Sign test? a. Assign a value of 1 b. Assign a value of 0 c. Assign a value of -1 d. Assign a value of 1000
b
What is the One Sample Median Test? a. It tests how likely an observed distribution is due to chance. b. It determines if there is a statistically significant difference between the means of two or more independent and unrelated groups. c. It determines if the sample median is statistically different or deviates from a hypothesized or known population median. d. It measures the strength of a linear association between two variables.
c
When would a One Sample Median Test be ideally used? a. When the data fits a particular distribution b. When you have a large sample size c. When testing "goodness of fit" to an assumed distribution d. When the data does not follow a normal distribution
d
The Wilcoxon-Mann-Whitney test compares ____ between two independent sets of data? A) Median B) Mean C) Bounds D) Shape
median