Post on 11-Jan-2016
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Research & Statistics Board Review DH227
Lisa Mayo, RDH, BSDHConcorde Career College
Continued search for truth using the scientific method
Systematic, objective laboratory, field and clinical investigations that lead to improvement of oral diseases and health care delivery
What is Research?
Methods used in any type of rsrch that increase the likelihood that info gathered will be relevant, reliable and unbiased
Steps include◦ Identification & statement of the problem◦ Formulation of a hypothesis◦ Collection, organization, analysis of data◦ Formulation of conclusions◦ Verification, rejection, modification of hypothesis
What is Scientific Method?
Identify problem Develop the hypothesis or research
questions Design the research plan Data collection – implementation Data analysis and interpretation Conclusions
Steps in the Research Process
Independent Variable◦ Manipulated variable to produce a response to the
dependent variable◦ Presumed cause
Dependent Variable◦ Shows effects of change, provides measurement data◦ Presumed effect◦ The DEPENDent variable DEPENDs on the
independent variable Example
◦ Independent = study grps vs independent studying◦ Dependent = graduation rates
Terminology
The following is correct of Dependent Variable:
a. Allows us to generalize from the sample of data to a larger group of subjects
b. Concerned with presentation, organization, and summarization of the data
c. The outcome of interest; should change in response to some intervention
d. The intervention, what is being manipulatede. Each element in the population has equal
chances of appearing: reduces the chance of bias
NBQ
The following is correct of Dependent Variable:
a. Allows us to generalize from the sample of data to a larger group of subjects
b. Concerned with presentation, organization, and summarization of the data
c. The outcome of interest; should change in response to some intervention
d. The intervention, what is being manipulatede. Each element in the population has equal
chances of appearing: reduces the chance of bias
NBQ
The variable controlled or manipulated in a study is
a. Population parameterb. Dependent variablec. Independent variabled. Variablee. Discrete number
NBQ
The variable controlled or manipulated in a study is
a. Population parameterb. Dependent variablec. Independent variabled. Variablee. Discrete number
NBQ
Extraneous Variable◦ Not germane to study, attempts are made to
control them or build them into the study Study Groups
◦ Control/experimental (2nd grp to compare) Sample
◦ Portion of population chosen to be studied in order to gain information about the entire population
Terminology
Reliability◦ Consistency of measurement, repeatability◦ The extent to which the method of measurement performs
consistently Single Blind
◦ When either subjects or raters, but not both, are unaware of subject placement into experimental grps
Double Blind◦ When both raters and subjects are unaware of which
treatment subject is receiving Validity
◦ The extent to which a scoring procedure measures that it was designed to measure
◦ Every step should be taken to maximize validity in a study
Terminology
Predictive Value (Sensitivity & Specificity)◦ Ability of a diagnostic test to accurately measure both
the presence and absence of disease Rate
◦ Numeric expression of disease in a population in which the # of the disease occurrence appears as the numerator and # possible occurrences appears as the denominator
◦ Usually includes a time dimension (year, months…)◦ Allows for valid comparisons from one year to the next◦ Ex: # of newborn deaths w/in first year of life per 1000
births ◦ Ex: % of people diagnosed w/oral cancer last year
Terminology
The extent to which the method of measurement performs consistently
A. RangeB. Standard DeviationC. ValidityD. ReliabilityE. ANOVA
NBQ
The extent to which the method of measurement performs consistently
A. RangeB. Standard DeviationC. ValidityD. ReliabilityE. ANOVA
NBQ
Radom Sample◦ Sample of subjects having equal & independent
chances of being selected◦ Pick names out of a hat
Stratified Sample◦ Subjects randomly chosen from a previously
subdivided population (diabetes vs no diabetes)◦ Divide class into 2 groups then select 2 members
from each group to participate Non-Random Sample
◦ One where bias enters in choice of participants
Research Samples
Systematic sample◦ Select every “nth” person to participate
Judgment Sample◦ Some familiar with the population selects the
sample◦ HIGH chance of bias!!
Convenience Sample◦ Group chose based solely on convenience◦ First 10 people to walk through door fill out
questionnaire
Research Samples
Descriptive Studies◦ Designed the describe the extent of a disease or
condition within a population and its relationship with other variables
◦ Determines who is getting the disease and where and when the disease is occurring
Experimental Studies◦ Tests hypotheses to establish CAUSE◦ Carried out under controlled situations◦ Uses control groups and tx groups
Analytical Studies◦ Aimed at formulating a hypothesis◦ Three main points: Retrospective, Prospective,
Longitudinal
Research Methods
Standard Deviation◦ Most commonly used method of dispersion in hyg rsrch
Formative Evaluation◦ Internal eval during early implementation
Summative Evaluation◦ Judges the merit of the program after it has been in
operation Descriptive Statistics
◦ Describes and summarizes a set of data numerically Inferential Statistics
◦ Generalize about the probable results of a large group when only a select portion of the grp has been observed
Eval & Rsrch
Evidence-based practice◦Using most current evidence to make
decisions about the care of individual patients
◦Evidence alone not sufficient to make decisions
◦Evidence ranking important See next slide
Epidemiology & Research
PYRAMID of EVIDENCE
Systematic Review & Meta-Analysis -“Gold Standard” Highest level clinical evidence -Synthesis of 2 or more randomized controlled trials answering the same question
As go up pyramid
Not all levels are equally useful for making patient care decisions
# studies decrease
relevance to answering clinical questions increase
Categories of community health rsrch◦ Epidemiologic rsrch to determine the presence
and distribution of disease in the population and factors that relate to the occurrence of disease within the population
◦ Clinical trials and tests of techniques and products to prevent and control disease
◦ Rsrch in educational techniques and the behavioral sciences related to oral health education
◦ Eval of community oral hl programs
Epidemiology & Research
Risk versus causality◦Risk identifies attributes that are assoc w/a
disease Case-control and cohort studies
◦Causality identifies factors that have been demonstrated to be causally related Randomized controlled clinical trials
◦Risk is established w/analytic studies◦Causality is established with experimental
studies
Epidemiology & Research
Risk versus causality: Types of risk attributesRisk factors
Strong identification of risk, causality is inferredCan be modified Important in making recommendations to patients
Risk indicatorsWeaker indication of riskCausality may be incorrectly assumedCan be modifiedShould be applied w/care in recommendations
Risk Predictors/Risk Marker/Demographic Risk FactorNon-modifiableHas no role in making recommendations to patient but
has importance in identifying target populations for community health programs
Epidemiology & Research
3 classifications of epidemiological rsrch1. Descriptive
Involves description, analysis, interpretation of data to eval a current event or situation
Does NOT test a hypothesis but helps increase understanding of a disease
Uses survey method with a cross-sectional design
2. Analytic3. Experimental
Epidemiology & Research
3 classifications of epidemiological rsrch2. Analytic
Observation of a disease or condition to id what causes disease
Does not establish causality – just observes Also called Observational or Development studies Non-interventional Purpose: help formulate a HYPOTHESIS for
experimental studies 3 Types
1. Cohort2. Case-Control3. Cross-Sectional
Epidemiology & Research
Epidemiology & Research
Analytic Research
Groups used
Cohort Uses defined grp
ProspectiveLongitudinal
Establishes incidence
Confirms risk factors
Case-Control Compares 2 grps (case & controls – those with & w/out disease
Retrospective (too many ethical compromises to use prospective)
Cross-Sectional
One grp & several sub-grps
Establishes prevalence
Cannot confirm risk factors
3 classifications of epidemiological rsrch3. Experimental
Test a hypothesis after analytic studies have inferred the cause of the disease
Deliberate manipulation of the supposed cause or controlling agent of a condition & observation of the result (longitudinal)
Establishes causality A randomized clinical trial is a well-controlled
experimental study with humans Experimental study that is not well controlled is
called quasi-experimental
Epidemiology & Research
3 classifications of epidemiological rsrch3. Experimental: Requirements
Use a control grpControl extraneous variablesRandomizationControl of errors in measurement (↑ validity &
reliability)Independent variable is manipulatedDependent variable is measured
Epidemiology & Research
3 classifications of epidemiological rsrch3. Experimental
Representative sample is required to allow for generalizations (also called inference)
If use small convenience samples: Replication studies are needed due to low external validity Repeated studies w/different samples
Multiple-site studies broaden the representation of the population = improve validity
Epidemiology & Research
3 classifications of epidemiological rsrch3. Experimental Study designs
1. Pre-test/Post-Test2. Post-Test Only3. Split mouth4. Cross-Over5. Time-Series (Repeated Measures)6. Blind (Making)7. Designs can be combined
Epidemiology & Research
3 classifications of epidemiological rsrch3. Experimental Study designs
1. Pretest/Post-Test Dependent variable is measured before &
after introducing the independent variable Provides a baseline measure for comparison
2. Post-Test Only Dependent variable is measured only after
introducing the independent variable Controls any possible effect of the pretest
procedure on the dependent variable3. Split mouth
Procedure unique to oral hl rsrch Side of mouth receives different interventions Controls subject-related variables
Epidemiology & Research
3 classifications of epidemiological rsrch3. Experimental Study designs
4. Cross-Over Ea grp receives a different intervention or
control & after a period, they are switched over the opposite tx
Controls subject-related variables5. Time-Series (Repeated Measures)
Dependent variable is measured several times over a specific period to determine whether its effect on the dependent variable holds over time
6. Blind (Making) Examiners measuring the dependent variable
w/out knowing the grp assignment Eliminates bias
Epidemiology & Research
A cross-over design research project includes what type of period:
A. Time seriesB. RandomC. WashoutD. PlaceboE. Both A and D
NBQ
A cross-over design research project includes what type of period:
A. Time seriesB. RandomC. WashoutD. PlaceboE. Both A and D
NBQ
Research always begins with a(n) _______ A) Trend B) QuestionC) Answer D) Survey E) All of the above
NBQ
Research always begins with a(n) _______ A) Trend B) QuestionC) Answer D) Survey E) All of the above
NBQ
Hypothesis◦ Predictive statement of the expected outcome or
relationship among variables◦ Answers rsrch questions in a manner that is
observable and measurable
http://www.youtube.com/watch?v=onVxp40MisI
Epidemiology & Research
Hypothesis◦ Null hypothesis
Negative statement of the hypothesis that assumes the absence of statistically significant differences between the sample grps
Ex: statement that no difference exists in the effectiveness of the 2 treatments
◦ Rsrch Hypothesis/Positive/Alternative Positive statement of the hypothesis is in terms that
express the opinion or prediction of the researcher Ex: statement that a difference exists in the
effectiveness of the 2 tx’s
Epidemiology & Research
Sampling◦ Random Sample
Increases external validity by controlling differences in study participants which allows for valid generalization of results to the population
Reduced bias in research
Epidemiology & Research
Sampling◦ Stratified Random Sample
Participants randomly chosen from an existing, know subdivided population
Results in the sample proportionately and accurately representing the subgrps in the population
Epidemiology & Research
Sampling◦ Systematic Random Sample
Selection of every nth member of the population from a list of the total population
The n depends on the size of the sample desired in relation to the population
Ex: 10% is every tenth member of the population Not a strictly random sample
Epidemiology & Research
Sampling◦ Convenience Sample
Study participants chosen on the basis of availability Used when access to the total population is not
feasible Bias is likely = reduces validity of sample and limits
the generalizability of study results
Epidemiology & Research
Sampling◦ Judgment or Purposive Sample
Study participants chosen by researcher or someone who has knowledge of the population
Biased Least valid method Generalization of results not possible
Epidemiology & Research
Sampling◦ Table of random numbers
Table composed of numbers that have been generated by a random technique used to select a random sample
Done by computers
Epidemiology & Research
Sampling◦ Sample Size: which one increases reliability of
results? Large sample
Accurately represents the defined population Increases precision, accuracy data collected Reduced standard error of sample mean Required for descriptive rsrch
Small sample May be necessary, depending on the purpose of the rsrch May lead to inaccurate conclusion when inappropriate for
the type of rsrch Require specialized statistics
Epidemiology & Research
Sampling◦ Grp Assignment
Assignment of participants to the grps of the study
Experimental Grp: receives independent variable
Control Grp: Does NOT receive experimental tx (independent variable)
Epidemiology & Research
To determine attitudes toward a fluoride mouthrinse program initiated in the local school system, a hygienist distributes a questionnaire to a group of parents. All of the following are likely limitations of this survey except:a. Incomplete responses by parentsb. Significant cost for conducting the researchc. Misinterpretation of questions by parentsd. Parents responding in the manner in which they think the hygienist wants them to respond
Question
To determine attitudes toward a fluoride mouthrinse program initiated in the local school system, a hygienist distributes a questionnaire to a group of parents. All of the following are likely limitations of this survey except:a. Incomplete responses by parentsb. Significant cost for conducting the researchc. Misinterpretation of questions by parentsd. Parents responding in the manner in which they think the hygienist wants them to respond
Answer
Science that describes, summarizes, analyzes and interprets numerical data for the purpose of making an inference about a population
Statistic: numerical character of a sample derived from the data collect
Parameter: numerical characteristic of a population
Statistics
1. Descriptive statistics/Inferential: statistics used to numerically describe & summarize data collected Mean, median, mode Measures of dispersion: range, variance, standard
deviation
2. Correlation Statistics: statistical measure for determining the strength of the linear relationship between 2 or more variables Graph curves: negative, positive skew
Statistics
3. Inferential Statistics Used to infer rsrch findings from the
sample to the general population from which the sample was taken
Used to test hypothesis, generalize results to a larger population of interest, provide evidence of causality
Statistics
1. Frequency distribution: scores arranged in order and by how often they occur
2. Scales of Measurement: nominal (name) ordinal (rank order)interval (equal intervals) ratio (all the above plus a true 0 point)
3. Graphing Techniques: X&Y4. Measurements of Central Tendency mean:
average median: midpoint mode: most frequently occurring score
5. Terms of Dispersion or Variabilityrange: difference between high and low scoresstandard deviation: dispersion around the mean (smaller sd = more homogeneous the grp)
1. Descriptive statistics
The most commonly used method of dispersion in oral hygiene research:
A. RangeB. Standard DeviationC. ValidityD. ReliabilityE. ANOVA
NBQ
The most commonly used method of dispersion in oral hygiene research:
A. RangeB. Standard DeviationC. ValidityD. ReliabilityE. ANOVA
NBQ
The arithmetic average of scores Most common measure of central tendency
Mean
Divides the distribution of scores into 2 equal parts
50% of the scores will be above and 50% will be below
NOT affected by extreme high or low scores
Median
The MOST frequently occurring score within the data matrix
Affects the skew of the graph
Mode
The gingival index (GI) scores of residents in the dementia wing were: 2,5, 2.75, 2.8, 3.0, 2.5, 2.0, 2.4, and 2.9. Which of the following represents the mean GI score?
a. 2.50b. 2.55c. 2.61d. 2.63e. 2.75
Question
The gingival index (GI) scores of residents in the dementia wing were: 2,5, 2.75, 2.8, 3.0, 2.5, 2.0, 2.4, and 2.9. Which of the following represents the mean GI score?
a. 2.50b. 2.55c. 2.61d. 2.63e. 2.75
Answer
The value that occurs with the greatest frequency:
A. MeanB. MedianC. ModeD. Positive SkewE. Negative Skew
NBQ
The value that occurs with the greatest frequency:
A. MeanB. MedianC. ModeD. Positive SkewE. Negative Skew
NBQ
The most common measure of central tendency: A. Mean
B. MedianC. ModeD. Positive SkewE. Negative Skew
NBQ
The most common measure of central tendency: A. Mean
B. MedianC. ModeD. Positive SkewE. Negative Skew
NBQ
When data is plotted using a normal (BELL) curve, the mean, median, and mode are EQUAL!
Board Alert!
Described how WIDE the scores are around a central point
Normal curve, central point would be the mean/median/mode
Range/Domain◦ Difference between the high and low score of a data matrix◦ Affected by extremely high or low scores
Standard Deviation◦ Represents the square root of the sample variance◦ SD is the MOST commonly used method of dispersion in oral
hygiene rsrch and reflects the range within the data matrix◦ Bigger the range or SD = wider distribution curve
Measures of Dispersion
Depends on 2 factors:◦ Mean ◦ Standard deviation
Mean identifies the position of the center Standard deviation determines the height
and width of the bell◦ Example: large standard deviation creates a bell
that is short and wide while a small standard deviation creates a tall and narrow curve
Bell Curves
• About 68% of the area under the curve falls within 1 standard deviation
•About 95% of the area under the curve falls within 2 standard deviations
•About 99.7% of the area under the curve falls within 3 standard deviations.
Bell Curves Rules
Mean, Median, Mode, SD
What is the most common measure of dispersion?
a. Meanb. Rangec. Data matrixd. Standard deviation
Question
What is the most common measure of dispersion?
a. Meanb. Rangec. Data matrixd. Standard deviation
Question
Ranking students from the individual with the highest GPA to the lowest is an example of a(an):a. Ordinal scaleb. Nominal scalec. Interval scaled. Ratio scalee. Count
Question
Ranking students from the individual with the highest GPA to the lowest is an example of a(an):a. Ordinal scaleb. Nominal scalec. Interval scaled. Ratio scalee. Count
Answer
Ex of narrow and wide distribution curvesWhich one has the greatest range or SD?
Ex of narrow and wide distribution curvesWhich one has the greatest range/SD?Range: Difference between the high and low score of a data matrix. Affected by extremely high or low scores
Notice that majority of scores fall between +1 and -1 SD when plotted on a Bell curve – ABOSLUTE!
BOARD ALERT!!
Most events in this world tend to fall into a bell-shaped curve called a normal distribution, sometimes called the _______
A. Left skewB. Positive skewC. Gaussian distributionD. Right skewE. None of the above
NBQ
Most events in this world tend to fall into a bell-shaped curve called a normal distribution, sometimes called the _______
A. Left skewB. Positive skewC. Gaussian distributionD. Right skewE. None of the above
NBQ
When graphed data asymmetrical appearance (not a Bell), it is said to be SKEWED
Positive Skew◦ When more scores fall into lower range◦ The right tail is longer; the mass of the
distribution is concentrated on the left of the figure. The distribution is said to be right-skewed, right-tailed, or skewed to the right
Negative Skew◦ When more scores fall into the higher range◦ The left tail is longer; the mass of the
distribution is concentrated on the right of the figure. The distribution is said to be left-skewed, left-tailed, or skewed to the left
2. Correlation Statistics Graph Curves
More scores are in the lower range with a few scores in the higher range: A. Mean
B. MedianC. ModeD. Positive SkewE. Negative Skew
NBQ
More scores are in the lower range with a few scores in the higher range: A. Mean
B. MedianC. ModeD. Positive SkewE. Negative Skew
NBQ
All of the following are effects of grouping data in tables and graphs except:a. Loss of detailb. Easier calculationc. More concise presentationd. Clearer identification of trendse. Specific detailed information
Question
All of the following are effects of grouping data in tables and graphs except:a. Loss of detailb. Easier calculationc. More concise presentationd. Clearer identification of trendse. Specific detailed information
Answer
Sample selected to generalize (infer) about the population at large
Parametric statistics◦ Population value defined by the statistics◦ Normally use a Bell Curve as data analysis◦ Large, random sample
Nonparametric statistics◦ Population parameters do not meet the assumption
required for parametric statistics◦ Data are nominal or ordinal in nature◦ Population from which the sample is drawn does not
have a normal distribution (skewed)◦ May or may not be a small sample
3. Inferential Statistics
Tests of Significance1. P Value2. T-test3. Correlation4. ANOVA5. F-test6. Chi-Square Test
3. Inferential Statistics
Reliability: the extent to which the method of measurement consistently performs. 2 types of examiner reliability1. Intrarater/Intraexaminer
Reliability indicated by same examiner is scoring equivalently time and time again.
Consistency of a single examiner in the application of an index or instrument over time to measure a disease/condition
2. Interater/Interexaminer Reliability indicates that consistency exists between
different examiners. Increased by calibration. Agreement among 2 or more examiners as they apply an
index or instrument over time to measure a disease or conditions
Inferential Statistics
Intrarater
Interrater
Sensitivity◦ Ability of a test to correctly id the PRESENCE of a disease
Specificity◦ Ability of a test to show the ABSENCE of a disease
Correlation Co-Efficient◦ Determine strength of relationship between 2 variables◦ Shows probable cause and effect◦ Given as a # between +1 and -1(Board Alert: the closer
the correlation co-efficient is to EITHER +1 or -1, the STRONGER the correlation!)
◦ Positive Correlation = as the value of x ↑, the value of y ↑◦ Negative Correlation = as the value of x ↑, the value of
y↓
Inferential Statistics
A study with high interrater reliability is a study in which:a. Results were not due to chanceb. One observer viewed the subjects the same way each timec. Two or more observers viewed the subjects the same wayd. The factor measures is the factor intended
to be measurede. Results are generalized to the population
from which subjects were drawn
Question
A study with high interrater reliability is a study in which:a. Results were not due to chanceb. One observer viewed the subjects the same way each timec. Two or more observers viewed the subjects the same wayd. The factor measures is the factor intended
to be measurede. Results are generalized to the population
from which subjects were drawn
Answer
Probability: use when testing a hypothesis Tells researcher if findings are significant beyond the
possibility of chance Also known as statistical level/alpha value Small p: indicate rare chance occurrence, decision
probably correct Large p: indicate that chance occurrence more likely Maximum p value to reject null hypothesis
◦ Oral rsrch = 0.05 (BOARD ALERT!)◦ P= 0.01 and0.001 indicate greater statistical significance
P Value
If significance is shown:◦ Experimental grp is different from control◦ Obtained difference is less likely to be a chance of occurrence
and is more likely due to the effects of the independent variable
◦ P=0.05 Observed diff. could be expected to occur by chance
◦ P > 0.05 Results r probably due to chance
◦ P < 0.05 statistically significant: 95% chance that what you found is due to
treatment, 5% chance what you found is due to error
P Value
P=0.01 1 out of 100 significant P=0.001 1 out of a 1000 significant
P Value
In statistical analysis, a p-value of 0.0001 denotes findings that are
a. Significantly differentb. Barely significantc. Very significantd. Very highly insignificante. Data are the same – no significance
NBQ
In statistical analysis, a p-value of 0.0001 denotes findings that are
a. Significantly differentb. Barely significantc. Very significantd. Very highly insignificante. Data are the same – no significance
NBQ
The proportion of those with true disease that is diagnosed with the new test as having the disease:
A. p-ValueB. Positive correlationC. Negative correlationD. SensitivityE. Specificity
NBQ
The proportion of those with true disease that is diagnosed with the new test as having the disease:
A. p-ValueB. Positive correlationC. Negative correlationD. Sensitivity (PRESENCE OF DISEASE)E. Specificity
NBQ
The ability of a diagnostic test to correctly identify the absence of disease:
A. p-ValueB. Positive correlationC. Negative correlationD. SensitivityE. Specificity (ABSENCE OF DISEASE)
NBQ
The subjects score on one scale is a fairly good predictor of that person’s score on the other scale. As the value of x variable increases, the value of y increases:
A. p-ValueB. Positive correlationC. Negative correlationD. SensitivityE. Specificity
NBQ
The subjects score on one scale is a fairly good predictor of that person’s score on the other scale. As the value of x variable increases, the value of y increases:
A. p-ValueB. Positive correlationC. Negative correlationD. SensitivityE. Specificity
NBQ
Significance of the difference between 2 mean scores
The t-test assesses whether the means of two groups are statistically different from each other
Memory Tip = T stands for Two
T-Test
Statistical measure for determining strength of the linear relationship between 2 variables◦ (+1) and (-1) are the strongest correlations
Positive Correlation: value of one increases so does the value of the other
Negative Correlation: value of one increases, the value of the other decreases
Correlation
Analyze the effects of 2 or more independent variables simultaneously within the same rsrch design (Ex: pancreatic cancer risk in diabetic patients who also use tobacco)
Determines interactions among the variables in multiple sample grps
Used to analyze 3 or more mean scores
Analysis of Variance (ANOVA)
The F-test is designed to test if 2 population variances are equal
Compares the ratio of two variances So, if the variances are equal, the ratio of
the variances will be 1 Parametric test
F-Test
The F-distribution is found by:Ratio of 2 independent chi-square variables Respective degrees of freedom
Since F is formed by chi-square, many of the chi-square properties carry over to the F distribution ◦ The F-values are all non-negative ◦ The distribution is non-symmetric ◦ The mean is approximately 1 ◦ There are two independent degrees of freedom:
1for the numerator, and 1 for the denominator◦ There are many different F distributions, one for
each pair of degrees of freedom
F-Test
Non-parametric test Used to determine if there is a statistical
difference between expected values and observed values
Chi-square is a statistical test commonly used to test a hypothesis◦ Chi-square is always testing the null hypothesis,
which states that there is no significant difference between the expected and observed result
Chi Square Test
Abstract: condensed version of the purpose Introduction Methods & Materials: detailed description of
the research instruments, equipment, procedures, methods of data analysis
Results: summary of all relevant data Discussion: eval and interpret findings Conclusion: Summarize the main points you
made and recommendations and review hypothesis
Research Reports: Boart Alert!!
To evaluate the statistical significance of the difference between 2 means when data meets parametric assumptions, one uses a _____, whereas to evaluate the expected values versus the observed values of 2 more samples when data meets nonparametric assumptions, one uses a ______. Which combination makes the statement correctly?
a. Chi-square test, t-testb. Chi square test, f-testc. t-Test, chi squared testd. t-test, f-teste. Correlation coefficient, chi square test
NBQ
To evaluate the statistical significance of the difference between 2 means when data meets parametric assumptions, one uses a _____, whereas to evaluate the expected values versus the observed values of 2 more samples when data meets nonparametric assumptions, one uses a ______. Which combination makes the statement correct?
a. Chi-square test, t-testb. Chi square test, f-testc. t-Test, chi squared testd. t-test, f-teste. Correlation coefficient, chi square test
NBQ
Which of the following parts of a research report should evaluate and interpret findings?:
A. ResultsB. AbstractC. DiscussionD. ConclusionE. Literature review
NBQ
Which of the following parts of a research report should evaluate and interpret findings?:
A. ResultsB. AbstractC. DiscussionD. ConclusionE. Literature review
NBQ
What is a body of techniques that uses observation, reason, and experimentation to further evidence:
A. Science measurementB. Scientific methodC. Evidence-based methodD. Retroactive methodE. Both A and B
NBQ
What is a body of techniques that uses observation, reason, and experimentation to further evidence:
A. Science measurementB. Scientific methodC. Evidence-based methodD. Retroactive methodE. Both A and B
NBQ