Quantitative Research Generalities Flashcards
Definition of Quantitative Research
Research methods dealing with numbers and anything that is measurable in a systematic way of investigation of phenomena and their relationships.
It is used to answer questions on relationships within measurable variables with an intention to explain, predict and control a phenomenon.
What is the purpose of Quantitative Research vs. Qualitative Research
Quantitative : Measuring outcomes, Generalize results from sample to population, answering the question How Much?
Qualitative : Deep understanding of the phenomenon (often exploratory), answering the questions What and Why?
How is Data Collected for Quantitative Research vs. Qualitative Research?
Quantitative : Standardized techniques (tests, scales, questionnaires, etc.).
Qualitative : Unstructured or semi structured techniques (interviews, open ended questionnaires, focus groups, etc.).
How is Data Analyzed in Quantitative Research vs. Qualitative Research?
Quantitative : Numerical comparisons and statistical inferences
How is the Research Question defined in Quantitative Research vs. Qualitative Research?
Quantitative : Clearly defined
Qualitative : Not (always) clearly defined
What is the goal of Quantitative Research vs. Qualitative Research?
Quantitative : Verify the theory, test hypothesis
Qualitative : Development of Theory, hypothesis
What are the key characteristics of Quantitative Research?
- Process is deductive, to test the idea/s
- Data is numeric to enable statistical analysis
- Pre-specified methods are used to ensure scientific rigor
What are the Key Objectives of Quantitative Research?
- Describe : the impact/burden of the problem
- Evaluate : the association between variables (examine relationships) vs. causation ; to test a treatment
- Predict : identify variables that predict outcomes
- Compare : identify differences between groups to provide a base of evidence for practic
Definition of Variables
- Independent variable : intervention
- Dependent variable : variable which is being observed -> should only vary in response to the independent variable
- Extraneous variable : need to control -> isolate effect of the independent variable on the dependent variable
- Otherwise : confounding variables
On what is based the validity of the trial
- comparability of groups at the beginning
- large numbers (a power calculation is essential)
- blinding of raters/ assessors and statisticians
- no confounding factors
- reliability of the measurements
What are the potential causes of bias in Quantitative Research ? `
- Researchers
- Components of the environnement/settings
- Individual participant and/or sample
- How groups were formed
- Measurement tools
- Data collection process
- Data and duration of study
- Statistical tests and analysis interpretation
Why is rigor important in Quantitative Research ?
- the validity of the study depends on it
- striving for excellence in research and adherence to detail
- precise measurement tools, a representative sample and a tightly controlled study design
- logical reasoning is essentiel
What is Experimental Research ?
- It is hypothesis-based
- Educated “guess” or presumption based on literature
- States possible relationship between two or more variables (dependent vs independent)
- Research study designed to test the relationship or predicted outcome described in the hypothesis
- 2 types : H0 vs H1 (in opposite to each other)
What are the potential problems of Experimental Research ?
- can be narrow scoped
- start with a research question, aim, objectives
- effect of sample size
Definition of Internal Validity
- Level to which the independent variable (eg: hamstrings weakness) caused the outcome of the study (eg: knee pain).
- Are you actually measuring what was intended to be measured ? (Eg: if you want to know about pain, does the scale actually measure pain?).
- Avoiding confounding factors.
What is External validity ?
- Generalize results
Which can cause difficulties. For example, the results of hamstrings training in 12-17 year old footballer may not be similar to the ones of 18-28 year old footballers.
What are the challenges in External validity ?
It randomly selects participants from the most diverse and representative populations, therefore:
- if sample is drawn from too wide a population it could lead to lack of meaningfulness in clinical situations
- if the sample is drawn from a very specific group generalization to other population is limited.
Describe Reliability principle
= the accuracy and repeatability of the measured outcome
= divided into inter-rater (between rater comparison) and intra-rater (within rater comparison)
Tell the difference between Validity and Reliability
Reliability is about the consistency of a measure
Validity is about the accuracy of the measure
What are the 11 steps of Quantitative Research Process ?
1) Research problem and purpose
2) Review of relevant literature
3) Study framework
4) Research objectives, question or hypothesis
5) Study variables
6) Study design
7) Population and sample
8) Measurements method
9) Data collection
10) Data analysis
11) Discussion of research outcomes
What are the research designs ?
- Descriptive : case-reports, surveys / qualitative
- Analytical : observational analytic / Experimental
What are the key elements of Descriptive research ?
- not analytical
- no hypothesis
- possibly large number of variables
- retrospective
- descriptive information to support or invalidate a theory
- help develop new hypothesis
Ex: case reports, case series, single case design, qualitative studies and surveys, cross sectional studies.
What are the key characteristics of Observational analytic design ?
- quantify the relationship between effect of intervention and exposure on outcome
- test an hypothesis
- measuring intervention/exposure
Ex: case control, cohort studies, cross sectional studies
What are the key elements of experimental research ?
- quantify the relationship between effect of intervention and exposure on outcome
- test hypothesis
- researcher manipulates intervention/ exposure
Ex: RCT
What is quasi experimental design ?
Test causality with sub-optimal variable control
Ex: before/after design
What is true experimental design ?
Test causality with optimal variable control
Ex: RCT