Step 4: Analyze the Data Flashcards
What are the 2 types of measurement errors in quantitative data?
Random errors - variable, unpredictable chance errors
Systematic - error occurs consistently
Who is the person contributing the information that will be analyzed in a quantitative and a qualitative study?
Quantitative
- study participant
- respondent
Qualitative
- study participant
- informant
- key informant
Who is the person undertaking the study in a quantitative and a qualitative study?
Researcher/investigator for both
What is being studied in a quantitative and a qualitative study?
Quantitative
- Concepts
- Constructs
- Variables
Qualitative
- Phenomena
- Concepts
What information is gathered in a quantitative and qualitative study?
Quantitative
- data
- numerical values
Qualitative
- data
- narrative descriptions
What are the connections between concepts that are being analyzed in a quantitative and qualitative study?
Quantitative
- Relationships (cause and effect, associative)
Qualitative
- patterns of associations
What is the logical reasoning process used during analysis of a quantitative and qualitative study?
Quantitative
- deductive reasoning (top down)
Qualitative
- inductive reasoning (bottom up)
What is the quality of evidence being analyzed in a quantitative and qualitative study?
Quantitative
- reliability
- validity
- generalizability
Qualitative
- trustworthiness
What is involved in the analysis of a mixed methodology study?
What is the focus?
Integration of the strands
- the strands are the qualitative and quantitative components
Meta-inference
- The insights derived from integrating qualitative and quantitative inferences at the end of the study
- Interpretative level after separate analyses have been completed
Focus
- congruence
- complementarity
What are strands in the mixed methodological study?
Parts of the mixed method design, typically either the qualitative or quantitative component
What is inference quality as it refers to a mixed methodological study?
The believability and accuracy of inductively and deductively derived conclusions
What is inference transferability as it refers to a mixed methodological study?
The degree to which conclusions can be applied to other similar people or contexts
What does the integrative framework for inference quality of a mixed methodological study consist of?
Design quality
Interpretive rigour
What is skewed data?
A long tail on one side or the other of a curve of a data set
What is a negative skew?
- Long tail on the negative side of the peak
- Also called “skewed to the left”
- Mean is shifted to the left of the peak
What is a positive skew?
- Long tail on the positive side of the peak
- Also called “skewed to the right”
- Mean shifted to the right of the peak
What type of skew shows the peak to the left of the mean?
Right or positive skew
What type of skew shows the peak to the right of the mean?
Left or negative skew
What is the extreme thoroughness and accuracy in research that is achieved through strict methods, processes, or procedures?
How is this expressed in quantitative and qualitative studies?
Rigour
Quantitative research, rigour is expressed as
o Validity
o Reliability
Qualitative research, rigour is expressed as
o Trustworthiness
o It may just be called rigour
Regardless of the paradigm used in a research study, what are the goals?
What is a study considered if it meets these goals?
MEMORY: CANT do it
C - consistency
A - applicability
N - neutrality
T - truth value
Rigorous if it meets these goals
How is the goal of truth value expressed in quantitative and qualitative studies?
Quantitative
- internal validity
Qualitative
- credibility
How is the goal of applicability expressed in quantitative and qualitative studies?
Quantitative
- external validity
Qualitative
- fittingness/transferability
How is the goal of consistency expressed in quantitative and qualitative studies?
Quantitative
- reliability
Qualitative
- auditability/dependability
How is the goal of neutrality expressed in quantitative and qualitative studies?
Quantitative
- objectivity
Qualitative
- confirmability
What does the statistics used in a statistical analysis depend on?
o Type of data to be analyzed
o Level of measurement of variables
o Assumptions about population distribution
o Study sample size
Where is the statistical analysis located in a paper?
The methods and results section
What type of statistical analysis may be used in a paper?
Descriptive - describes data
Inferential - tells about the greater population
What is the index that describes a characteristic of an entire population such as an average when performing a statistical analysis?
Parameter
What is a parameter in a statistical analysis?
o Index that describes a characteristic of an entire population
o i.e. averages and percentages
What is an index calculated from sample data as an estimate of a population parameter when performing a statistical analysis?
Statistic
What is a statistic?
o Index calculated from sample data as an estimate of a population parameter
What are the 4 levels of measurement?
What do they help us determine?
nominal
ordinal
interval
ratio
Determines which summary statistics, graphs, and analysis are possible/sensible
What is the process of assigning numbers to objects, where the number represents the quantity of the attribute under study?
Measurement
Describe the nominal level of measurement
- Most basic level
- Also called categorical or qualitative
- Data is classified
- Variables are named
o Examples are sex, colour, preferred type of chocolate - Values can be stored as a word, text, or given a numerical code but the numbers to not imply order
- To summarize we use a frequency or percentage
- Cannot calculate mean or average value
- Visual representations – pie, column/bar, stacked column/bar charts
What level of measurement is data classified but does not use rank ordered and used strictly for non-numerical data such as sex?
nominal
Which type of data can be represented by pie charts, bar/column charts or stacked column/bar charts?
nominal
Describe the ordinal level of measurement
- Data is ordered
- Meaningful order but intervals between each value on the scale may not be equal
o Think like the always to never scale, satisfaction scales, or ranking things from first to tenth (even runners in a race) - Summarized as frequencies
- Mean may be calculated, just ensure the calculation is justified
- Visual representations – column/bar chart
Which level of measurement does not allow for calculating the mean or average?
nominal
Which level of measurement may sometimes have a mean calculated, but other times, it does not make sense to calculate a mean?
Ordinal
Which level of measurement is summarized as a frequency?
nominal
ordinal
Describe the interval/ratio level of measurement
- Data is measurable
- Meaningful order but intervals between each value on the scale have consistent and quantifiable differences between them
o Interval has no true zero, the zero is arbitrary and does not mean a complete absence of the variable
i.e. temperature in Celsius – 0C doesn’t mean an absence of temperature
i.e. test score – 0% doesn’t mean you didn’t take the test
o Ratio has a true zero
Cannot have negative numbers
i.e. weight, height, number of kids - Also called scale, quantitative, or parametric
- Examples include age, weight, number of customers etc
- Discrete – uses whole numbers
- Continuous – uses fractional numbers
- Mean, median and standard deviation can be calculated
- Visual representations – bar chart, histogram, box plots, line charts
In which level of measurement is there meaningful order, but the intervals between each value on the scale have consistent and quantifiable differences between them?
Interval/ratio
What is the difference between the interval and ratio levels of measurement?
Interval has no true zero, the zero is arbitrary and does not mean a complete absence of the variable
i.e. temperature in Celsius – 0C doesn’t mean an absence of temperature
i.e. test score – 0% doesn’t mean you didn’t take the test
Ratio has a true zero
Cannot have negative numbers
i.e. weight, height, number of kids
What is the use of whole numbers in statistical analysis called? What level of measurement uses whole numbers?
Discrete
Interval/ratio
What is the use of fractional numbers in statistical analysis called? What level of measurement uses whole numbers?
Continuous
Interval/ratio
Which level of measurement allows for calculating the mean or average?
Interval/ratio
What are non-parametric statistics?
- No rigorous assumptions avoid distributions of the variables
- Used with small samples
- Nominal or ordinal data
- When distribution is severely skewed
What are parametric statistics?
- Assumes normal distribution of the variables
- Requires interval/ratio measures
- Participants should be randomly assigned
- Homogeneity of variance
What are the non-parametric tests of differences?
chi square
What are the parametric tests of differences?
- t-tests (independent or dependent)
- ANOVA
- MANOVA
What are the non-parametric tests of association?
- Phi coefficient
- Spearman rho
- Kendall tau
What are the parametric tests of association?
Pearson coefficient - r
Multiple regression - R
Describe the Chi Square test
Tests of Differences – Non-Parametric
* Used with nominal/ordinal data
* Compares observed frequencies with expected frequencies
* Expected frequencies are the number of cases in each case if null is true
* Fischer’s exact probability test
o Used for small sample sizes < 6 in each cell
* i.e. test for differences in study groups on marital status, racial makeup, and education level
Describe the independent group t-tests
Tests of Differences – Parametric
o Subjects in 2 groups are not the same people and not connected in any systematic way
i.e. caffeinated coffee and intraocular pressure (N=100)
Group 1 – regular coffee n=50
Group 2 – decaffeinated coffee n=50
IV = group – nominal level
DV = intraocular pressure – ratio level
Describe the dependent group t-tests
Tests of Differences – Parametric
- Paired, correlated groups t-test
- Some group of subjects is measured on more than one occasion
- Sample fluctuation is lower
- i.e. diabetics on a weight loss program
Describe ANOVA tests
Tests of Differences – Parametric
- Analysis of variance
- When the means of 3 of more groups are compared
o Assumes independence of groups - Used to analyze all groups simultaneously by dividing the (alpha) between all tests
- Dependent variables should be continuous and normally distributed
- Statistic calculated is the F ratio
o MSB – means between the groups
o MWW – Variation of individual scores within each of the groups - F = MSB / MWW
Describe MANOVA tests
Tests of Differences – Parametric
- Multivariate analysis of variance
- Examines the difference between mean scores of two or more groups on two or more dependent variables that are examined at the same time
- Repeated measures ANOVA – group means are compared at multiple points
Describe the Spearmen’s Rho and Kendall Tau tests
Tests of Association/Relationship – Non-Parametric
- Used for ordinal data
- Varies from -1.0 to +1.0
Describe the Pearson Coefficient - r test
Tests of Association/Relationship – Parametric
- Indicates the magnitude and direction of a linear relationship between two variables
- Varies from -1.0 to +1.0
Describe the multiple regression - R test
Tests of Association/Relationship – Parametric
- Relationship between interval dependent variable and several independent variables
- What independent variable contributes to explain dependent variable
- Varies from -1.0 to +1.0
What tests use nominal or ordinal data? What are examples of these tests?
Non-parametric tests
Tests of differences - chi square
Tests of association - phi coefficient, Spearman rho, Kendall Tau
What type of tests uses nominal data and compares the observed frequencies with the expected frequencies?
Chi square test
You are running a trial for a new blood pressure medication. One group receives the new medication while the other group uses standard therapy. What type of statistical analysis should be run on the resulting data?
Independent group t-tests
o Subjects in 2 groups are not the same people and not connected in any systematic way
You are a nurse working in a hospital and you notice that many of your patients seem to have COPD. You want to know if your city actually has higher than expected rates of COPD for your country or if it’s just your anecdotal evidence that there are more patients with COPD. What test would help you determine this?
Chi Squared test
What tests use interval/ratio data and has 2 groups that are not the same people and they are not connected in any systematic way?
Independent group t-tests
You are running a study to determine if patient education will improve the lives of your obese patients. At the beginning of the study, the 50 participants came to see you to have their weight recorded. For the next 8 weeks, all 50 people participate in a 1 hour meeting each week. You cover a different topic each week regarding obesity (risks, diet, exercise etc.). At the end of the study, the participants come back to be measured a second time.
What type of statistical analysis would tell you if your patients lost a statistically significant amount of weight over the 8 week program?
Dependent group t-tests
(same group measured on more than one occasion)