Variable is

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SOWK 6003 Social Work
Research
Week 4
Research process, variables, hypothesis, and
research designs
By Dr. Paul Wong
Research Process?
1.
2.
3.
4.
5.
6.
7.
Problem formulation
Designing the study
Data collection
Data processing
Data analysis
Interpreting the findings
Writing the report
Purposes of Research
1.
2.
3.
4.
5.
Exploration
Description
Explanation
Evaluation
Multiple purposes
This week we will focus on the first 2 steps in a
research process
Formulating a problem
and Designing a study
Operationalization of Concepts
• Concept as a mental image that symbolizes an idea, an
object, an event, a behavior, a person and so
on……word that people agree upon to symbolize
something.
• Attributes are concepts that can be grouped together to
form a broader concept.
• Variable is
- something of interest to us that can take on different values;
- an element in a research project that, when measured, can take
on more than one value
- A variable is a characteristic that has two or more values.
Relationships between Variables
• Correlations
• Correlational relationship simply says that
two things perform in a synchronized
manner.
Think about this relationship!
Weather and fashion,
how are they relate
to each other?
Types of Variables
Independent Variables (IVs) vs. Dependent Variables (DVs)
IV is a variable that explains or causes something,
and is not depending on the other variables. It is
what the researcher (or nature) manipulates.
DV is the variable which is the effect, being
explained or caused.
Extraneous Variables vs Mediating Variables
• Extraneous variables represent alternative
explanations for the relationships that are observed
between the independent variable and dependent
variables
• Mediating Variable is the mechanism by
which an independent variable affects a
dependent variable. Sometimes it is also
referred as intervening variables.
How do
Extraneous
Variables come
in to the picture
between weather
and fashion?
Continuous, Discrete, and Dichotomous Variables
Continuous variable has an infinite number of
different values between the highest and lowest
score. E.g., ?
Discrete variable has a limited and countable
number of distinct steps between the highest
and lowest score. E.g.,?
Dichotomous variable has only two levels. E.g.,?
What is research design?
http://www.csulb.edu/~msaintg/ppa696/696preex.htm
When we talk about study design, we need
to consider the following aspects:
1.
2.
3.
4.
Nature
Setting
Time
Participants
Nature
– Experimental Design - investigation that involves manipulation and
control of an independent or treatment variable with the intent of
assessing whether the independent variables causes a change in the
level of a dependent variable. Note: Randomization : random
assignment to the control and experimental group, which is not equal to
random sampling. It is about the reduction of systematic error such as
selection bias.
– Quasi-Experimental Design - research study set up to resemble a true
experiment but that does not involve random assignment of the
participants to a group or manipulation and control of a true independent
variable, instead relying on measuring groups based on pre-existing
characteristics. (Beins, 2009)
– Pre-Experimental Design - the features of experimental design and
quasi-experimental design are not present.
Setting
• Applied Research: take place in a natural environment
where people are acting as they normally do. It usually
attempts to address practical questions rather than
theoretical questions
•
Basic Research is more likely to occur in a laboratory
or other controlled setting. It tests or expands on
theory, with no direct application intended. (Beins, 2009)
Time
• One time: Cross-sectional/One
shot/Posttest only
• Two time: pretest – posttest design
• More than two times: Longitudinal
• Many many times: Time Series
Participant/Subject
• One person – Case study
• One group – A cohort
• More than one person
• More than one group –
Comparison study
Treatment/intervention
Data Source
• Qualitative
–
–
–
–
–
–
–
Observations
Journal/Diary/Self report
Indepth Interview
Focus Group
Art work
Archives
Documents
• Quantitative
– Measurements through self-administered questionnaires (by
hand, by mail, or online)
– Interview survey (telephone, home visit)
– Health indicators (BP, skin temperature, saliva cortisol etc.)
Research rigor (means good standard)
• Ethical Rigor - concerns about ethical
consideration
• Methodology Rigor
1. The matching of research questions with the
research methods
2. The appropriateness and reliability of the data
collection method
3. The representativeness of the samples
4. The generalizability of the data
Rigor of Data Collection Method
(we will talk more about them next week)
Reliability :
– consistency of measurement over-time (test-retest reliability)
– consistency of measurement by different rater (interrater reliability)
– consistency of measurement on different subgroup (split-half reliability)
– consistency of measurement on items of the measurement tools (internal
consistency reliability. Cronbach’s alpha)
Validity:
- refers to the extent to which an empirical measure adequately reflects the
real meaning of the concept under consideration.
•
•
•
•
•
Face validity
Content validity
Criterion-related validity
Construct validity: convergent and discriminant validity
Factorial validity
•
•
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•
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•
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Establishing Trustworthiness (Lincoln & Guba, 1999)
Credibility
- activities increasing the probability that credible findings will be produced:
prolonged engagement, persistent observation and triangulation);
- an activity that provides an external check on the inquiry process (peer
debriefing);
- an activity aimed at refining working hypotheses as more and more
information
becomes available (negative case analysis);
- an activity that makes possible checking preliminary findings and
interpretations
against archived “raw data” (referential adequacy);
- an activity providing for the direct test of findings and interpretations with
the
human sources from which they have come (member checking).
• Confirmability
• - Inquiry audit: auditor to examine the
products: whether findings are grounded in
• the data
• - A sample of findings is traced back, via
audit trail to the raw data.
In class activity 1
Discussions on last week’s
homework
In class activity 2
How to write a research proposal?
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