2. Quantitative Research
What is quantitative research?
Quantitative research collects and uses numerical data to
explore, describe, explain, or predict trends or phenomena.
Quantitative research emphasizes objectivity and the control of
contextual factors that may impact the results.
Quantitative research states hypotheses and relies on statistical
analysis to support conclusions made regarding the
hypotheses.
3. Reasons for Quantitative Research
Exploratory
Investigates issues with the goal of providing insight and information to
the researcher
Use pilot studies to test feasibility or value of working in an area; focus
groups to guide survey design
Description
Describe the current situation or classify situations, events or groups.
Often use large scale data sets -NELS, High School and Beyond, etc.
Surveys; correlational studies
4. Reasons for Quantitative Research
Explanation
Build, enrich and explain theories
Test theories using quantitative methods
Prediction
Establish predictors of some behavior
Two types of variables – predictor and criterion (outcome)
Regression analysis is one statistical procedure used for prediction
Evaluation
Evaluates programs for their efficacy
Come in different forms and serve different functions
5. Types of Quantitative Research
Survey Research
Collect quantitative data to address questions about the
current state of a population or phenomena.
Can address preferences, attitudes, opinions, concerns,
interests
Correlational Research
Determines if a relationship exists between two quantitative
variables
Measure the strength of the relationship
6. Types of Quantitative Research
Causal-Comparative Research
Establish a cause, or reason, for a behavior or other
phenomena after the event, or cause, has already occurred.
Involves an independent-dependent variable relationship.
Experimental Research
A collection of research designs that uses one or more variables
that are manipulated to understand the effect on a dependent
variable.
Allows for control of variables not relevant to the research.
7. Types of Quantitative Research
Action Research
Conducted by school administrators, teachers, or any other
stakeholder in the teaching-learning environment
Primary focus is on the way schools operate, teachers teach
and students learn
8. Four Parts of Quantitative Research
Measurement
Sampling
Research Design
Statistical Procedures
9. Properties of Measurement
Reliability
Consistency
Random error
Validity
Interpretation/Use
Most Important Property
Systematic error
Reliability is necessary but not sufficient condition
for validity
10. Properties of Sampling
Population v Sample
Sampling Methods
Probabilistic (e.g., random)
Non-probabilistic (e.g., convenience)
Key is that sample is representative of population to
make a generalization in interpretation
11. Research Design
How to set up data collection to minimize counter
interpretations to the results
Control/Comparison Groups
Random Assignment
12. Random Selection vs. Random Assignment
Random selection--Each person of a population has
an equal chance of being included in the sample.
Random assignment--Each person of a sample has
an equal chance of being assigned to particular
group.
14. Criteria for Evaluating Social Research
Construct validity
Refers to inferences made from measured variables to
theoretical constructs
Examines how well assessment “matches up with” the
construct.
Internal validity
Examines the extent to which the relationship between two
variables is isolated from the influences of additional variables.
15. Criteria for Evaluating Social Research
External validity
Addresses the concern of how well does the relationship
between two variables generalize across settings, samples, and
times.
Statistical conclusion validity
Addresses issue of how the use of statistics shape inferences
and interpretations