Transcript RCPT 436 Research & Technology Applications

Research Design
RCPT 436 Research &
Technology Applications
Units of Analysis
Individuals: students, participants,
patients
Groups: classes, families, gangs
Organizations: universities,
churches, recreation departments
Social Artifacts: books, paintings,
songs, editorials, buildings
A word of warning…
 On average, students from
Springfield score higher on the
SATs then students from
Shelbyville. What can we
conclude about Lisa Simpson?
NOTHING! An Ecological Fallacy results when
you make conclusions about individuals based
upon aggregate data.
Variables
Definition: discrete phenomenon
that can be observed in at least
two mutually-exclusive categories
– Dependent variable
– Independent variables
– Intervening variables
Independen
t Variable
Watching a
Snickers
Commercial
Intervenin
g Variable
Hunger
Dependen
t Variable
Buying a
Snickers from
Vending Machine
What other
(independent)
variables
could explain
our purchase
of a Snickers?
Defining the scope
Purpose statement
Significance statement
Theory or conceptual roadmap
Which Hypothesis is Which?
Hypothesis
– Null hypothesis
– Non-directional hypothesis
– Alternative hypothesis
 Men will perform better than women on
standardized tests.
 The average scores for men and women will be
different.
 There will be no statistical difference between
test scores
Internal Validity
Determine whether a given
program is working, if it meets
standards, or how it compares to
other programs
Properly demonstrates a causal
relationship between two variables
External Validity
Ability to generalize findings to the
“real world” or beyond the sample
Results should be reproducible
across different experimental
settings
Threats to External Validity
1.
2.
3.
4.
5.
6.
7.
Selection bias
Experimental settings
Testing
Multiple treatment interference
Inadequate operational definition
Hawthorne effect
Selection interacting with any
extraneous variables
Experimental Design
1. Random selection of sample
2. Pretest
3. Random assignment to
experimental and control groups
4. Post-test
Variations
Quasi-experimental design – study
participants not randomly assigned
to control or experimental group
Pre-experimental – no control
group
Non-experimental – individuals are
observed or surveyed
Qualitative Designs
Ethnography: holistic understanding
(participant observation)
Case study: in depth study of a single
phenomenon (visionary)
Content analysis: written, visual, or
recorded documents (profanity on TV)
Historical study: studying the past
(primary or secondary data; be
skeptical)
Rigor determined by truthfulness,
applicability, and consistency