VITTORIO CESCHI’S SUMMARY
CM2005-Quantitative Methods in Media & Communication
Book + Lecture Summary
Week 1
The Use of Theory
Variables in Quantitative Research – a variable refers to a characteristic or attribute of an
individual or an organization that can be measured or observed and that varies among the
people or organizations being studied
➢ It may vary in two or more categories or on a continuum of scores, and can be
measured or assessed on a scale
Variables are distinguished by two characteristics:
1. Temporal order: one variable precedes another in time; it is said that one variable
affects or (probably) causes another variable; quantitative researchers think about
variables in an order from “left to right” – cause-effect presentations
2. Their measurement:
- Independent variables are those that (probably) cause, influence, or affect
outcomes - also called predictor variables
- Dependent variables are those that depend on the independent variables – they
are the outcomes or results of the influence of the independent variables
- Mediating (intervening) variables stand between the independent and dependent
variables, mediating the effects of the independent variable on the dependent one
• A mediating or intervening variable explains the how or why of an (observed)
relationship between an independent variable and its dependent variable
- Moderating variables are new variables constructed by a researcher by taking
one variable and multiplying it by another to determine the joint impact of both
• (e.g., age X attitudes toward quality of life)
- Control and confounding variables
o Control variables: special type of independent variable that researchers
measure because they potentially influence the dependent variable; they
may be demographic or personal variables (e.g. age or gender) that need
to be “controlled” so that the true influence of the independent variable on
the dependent can be determined
o Confounding (or spurious) variable: not actually measured or observed in
a study; it exists, but its influence cannot be directly detected →
researchers comment on its influence after the study has been completed,
as those variables may have operated to explain the relationship between
the DV and IV, but they were not or could not be easily assessed (e.g.
discriminatory attitudes)
,Definition of a Theory – a theory is an interrelated set of constructs (or variables) formed
into propositions, or hypotheses, that specify the relationship among variables – i.e. why does
X influence Y or viceversa? → theory
➢ A discussion about this theory would appear in a section of a proposal on the
literature review or on the theory base, the theoretical rationale, or the theoretical
perspective
Another aspect of theories is that they vary in their breadth of coverage – three levels:
1. Micro-level theories provide explanations limited to small slices of time, space, or
number of people
2. Meso-level theories link micro and macro levels; theories of organizations, social
movements, communities…
3. Macro-level theories explain larger aggregates, such as social institutions, cultural
systems, and whole societies
Placement of Quantitative Theories – in quantitative studies, one uses theory deductively
and places it toward the beginning of the proposal for a study; with the objective of testing a
theory, the researcher advances a theory, collects data to test it, and reflects on its
confirmation or disconfirmation by the results; the theory becomes a framework for the
entire study, an organizing model for the research questions or hypotheses and for the data
collection procedure
➢ A general guide is to introduce the theory early in a plan or study: in the introduction,
in the literature review section, after hypotheses or RQ, or in a separate section
Writing a quantitative theoretical perspective – The topics to include in a quantitative
theory discussion are the theory to be used, its central hypotheses or propositions,
information about past use of the theory and its application, and statements that reflect how it
relates to a proposed study; check pg. 9 to 11 for steps
Variation in Theory Use in Qualitative Research – qualitative inquirers use theory in their
studies in several ways:
1. Used as a broad explanation for behaviour and attitudes, and it may be complete with
variables, constructs, and hypotheses
2. Researchers use a theoretical lens or perspective in qualitative research which
provides an overall orienting lens for the study of questions of gender, class, and race
(or other marginalized groups)
3. Theory becoming the end point → an inductive process of building from the data to
broad themes to a generalized model or theory
• Propositional generalization: the researcher’s summary of interpretations and
claims – to which is added the researcher’s own personal experiences, called
“naturalistic generalizations”
• Pattern theories: explanations that develop during naturalistic or qualitative r.
– systems of ideas that informs
4. Some qualitative studies do not employ any explicit theory
,Mixed Methods Theory Use – theory use in mixed methods studies may include theory
deductively, in quantitative theory testing and verification, or inductively as in an emerging
qualitative theory or pattern; here, theory can also be thought as a theoretical lens or
perspective
➢ In using theory in a mixed methods proposal:
- Determine if theory is to be used
- Identify its use in accord with quantitative or qualitative approaches
- If theory is used as in a transformational strategy or inquiry, define this strategy
and discuss the points in the proposed study in which the emancipatory ideas will
be used
Research Questions and Hypotheses
Qualitative Research Questions – the central question is a broad question that asks for an
exploration of the central phenomenon or concept in a study; the following are guidelines for
writing broad, qualitative research questions:
➢ Ask one or two central questions followed by no more than five to seven subquestions
➢ Relate the central question to the specific qualitative strategy of inquiry
➢ Begin the research questions with the words what or how to convey an open and
emerging design
➢ Focus on single phenomenon or concept
➢ Use exploratory verbs that convey the language of emerging design
➢ Use these more exploratory verbs that are non-directional rather than directional
words that suggest quantitative research, such as “affect, influence, impact, cause,…”
➢ Expect the research questions to evolve and change during the study in a manner
consistent with the assumptions of an emerging design
➢ Use open-ended questions without reference to the literature or theory
➢ Specify the participants and the research site for the study
Quantitative Research Questions and Hypotheses – quantitative RQ inquire about the
relationships among variables that the investigator seeks to know; quantitative hypotheses,
on the other hand, are predictions the researcher makes about the expected relationships
among variables; guidelines for good quantitative RQ are as follows:
➢ The use of variables in RQ or hypotheses is limited to three approaches:
a. The researcher may compare groups on an IV to see its impact on a DV
b. The researcher may relate one or more IV to one or more DV
c. The researcher may describe responses to the independent, mediating, or
dependent variables
➢ The most rigorous form of Quantitative research follows from a test of a theory
➢ The IV and DV must be measured separately, reinforcing the cause-effect logic of
Quantitative research
➢ Write only RQ or hypotheses, not both, unless the hypotheses build on the RQ; if
hypotheses are used, there are two forms:
, • Null hypotheses: makes prediction that in the general population, no
relationship or no significant difference exists between groups on a variable
- i.e. in the population there is no relationship/there is…
• Directional hypotheses: making a prediction about the expected outcome,
basing this on previous literature and studies on the topic suggesting such
potential outcome – i.e. increases/decrease
• Nondirectional: a prediction is made, but the exact form of differences is not
specified because the researcher doesn’t know what can be predicted from past
literature – i.e. affects/influences
Lectures
Introduction Lecture: RQ, hypotheses, variables
Theory: an interrelated set of variables formed into hypotheses that specify the relationship
among variables, with the purpose of explaining natural phenomenon
Theoretical rationale: provides explanation or prediction about why and how variable X
(dependent) would influence variable Y (independent)
Independent Variables (IV) those that probably influence or affect outcomes (treatment,
manipulated, antecedent, predictor)
Dependent Variables (DV) those that are presumed result of the influence of the IV
(criterion, outcome, effect)
Hypotheses versus Opinions – what is the main difference?
➢ Hypotheses are tested with statistics, opinions are not
➢ Hypotheses can then be answered by saying TRUE or FALSE
➢ Hypotheses are followed up by data!
Two types of Hypotheses
1. Null hypotheses (H0)
- No difference or change
- Never stated, always implied
2. Alternative hypotheses (H1)
- Statement of prediction
- Actual research hypotheses
The goal of hypothesis testing is to reject one hypothesis and accept the other
Type of H1 Hypotheses
➢ Directional hypothesis
- Difference or effect in particular direction – e.g. media violence
increases/decreases mood
