This document outlines the major differences between quantitative and qualitative research approaches. Quantitative research relies on numerical data and statistical analysis to test hypotheses and identify cause-and-effect relationships. It assumes a single objective reality. Qualitative research relies on words and descriptions to understand perspectives and experiences. It assumes multiple subjective realities. Quantitative research aims to explain and predict, while qualitative research aims to understand social phenomena from participant perspectives. The two approaches also differ in their methods, study designs, researcher roles, contexts of findings, means of verification, and types of reasoning employed.

1. Quantitative Versus
Qualitative
John B. Schorling, M.D., M.P.H.
Professor of Medicine and Public Heath Sciences
James R. Martindale, Ph.D.
Assistant Professor of Research and Public
Health Sciences

2. Objectives:
 Understand the major differences between
quantitative and qualitative approaches to
doing research

3. “If we knew what we were
doing, it wouldn’t be called
research, would it?”
Albert Einstein

4. The Right and the Left
 Quantitative research - numbers,
numbers, numbers
 Qualitative research - words, words,
words

5. Quantitative vs. Qualitative:
Assumptions about the World
 Based upon the idea
of “logical
positivism”, that is,
there is a singular
reality with stable,
social facts that are
separate from the
feelings and beliefs
of individuals.
 Based on the notion
of “constructivism”,
which assumes
multiple realities that
are socially
constructed through
individual and
collective
perceptions or views
of the same
situation.

6. Quantitative vs. Qualitative:
Research Purpose
 Seeks to establish
relationships and
explain causes of
changes in
measured variables.
That is, the goal of
science is to explain
and predict.
 Concern is with the
understanding of the
social phenomenon
from the
participants’
perspectives. This
requires, to some
degree, researcher
participation.

7. Quantitative vs. Qualitative:
Methods and Process
 The scientific
method, also known
as a priori or pre-
established design.
 Use of emergent
design utilizing
constant
comparison and
revision.

8. Quantitative vs. Qualitative:
Prototypical Studies
 Experimental or
correlational designs
are used to reduce
error, bias and the
influence of
extraneous
variables--control of
bias is through
design.
 Use of ethnography,
which helps readers
understand the
multiple
perspectives of the
situation by the
persons studied.
Subjectivity in data
analysis and
interpretation is
acknowledged.

9. Quantitative vs. Qualitative:
Researcher Role
 Detachment from
study in order to
avoid bias.
 Immersion in
situation and the
phenomenon being
studied.

10. Quantitative vs. Qualitative:
Context
 Context-free
generalizations
 Generalizations are
contextually-bound.

11. Quantitative vs. Qualitative:
Precision
 Obtained through
the use of
measurement and
statistics
 Provided by detailed
description of
phenomenon

12. Quantitative vs. Qualitative:
Verification
 Results replicated
by others.
 Extension of
understandings by
others.

13. Quantitative vs. Qualitative:
Explanation
 Traditionally,
parsimonious
explanations were
sought, but this may
be changing due to
technology.
 Summary through
narrative--
importance is placed
on reducing
complex realities to
simple explanations.

14. Quantitative vs. Qualitative:
Logical Reasoning
 DEDUCTIVE--
What’s the classic
example?
 INDUCTIVE--
anyone have an
example?

15. Quantitative vs. Qualitative:
Conditional Conclusions
 Statements of
statistical
probability.
 Tentative summary
interpretations.

16. Types of Quantitative Studies
 Descriptive
 True experimental
 Quasi-experimental
 Correlational
 Predictive