Research 36-377
Dr. Wally J. Bartfay
“When the solution is
simple…God is answering”
(Albert Einstein, 1879-1955)
Observational Measurement
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Although most common in qualitative
research, it is used to some extent in all
types of studies (e.g., esp. with children)
Measurement in qualitative research is not
distinct from analysis b/c tend to occur
simultaneously
Observational Measurement
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Not as simple as it sounds
Have to 1st decide what is to be observed
2nd, need to determine how to ensure that every
variable is measured consistently in same
manner
Tend to be more subjective so less credible
method
Must pilot test technique & interrater reliability
Unstructured observations
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Involves spontaneous observing & recording with
little prior planning
Certain risk of loss of objectivity here
Notes are usually taken during observation period or
shortly after
“Chronologs” are detailed descriptions of subjects in
a natural environment {very intense so can’t record
for more than 30 mins at a time}
Some studies, video-recordings may be made
Structured Observations
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1st step is to define exactly what is to be observed
2nd step, need to determine how observations will be
recorded & coded
Often a “category system” is developed for
organization & sorting behavior or events, which are
mutually exclusive (e.g., infant is eating, sleeping,
playing, running, climbing, sitting)
Checklists are also used to tally-up how often
behaviors or events occur
Questionnaires
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Are printed self-report forms designed to elicit
specific information (e.g., knowledge, attitudes,
intentions, opinions etc)
Subject can’t elaborate, so can be a limitation
If response rate is less than 50% (esp. with mailedtype), the representativeness is in question
Can employ strategies to increase response rates
(e.g., multiple mailings, monetary incentive, prizes)
Scales
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Types of self-report, more precise than
questionnaires & is based on mathematical theory
Rating scales are crudest form (e.g., rate pain on
scale of 1 to 10)
Likert scales are designed to determine “degree and
magnitude” of opinions or attitudes on various topics
(e.g., strongly disagree, disagree, neutral, agree &
strongly agree)
Visual analogue scales (VAS) or magnitude scales
(subject asked to place mark on vertical or horizontal
line following a specific question)
The concepts of measurement in
research: Nominal scales
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4 levels 1st described by Stevens (1946): “NOIR”
(1) Nominal-scale measurement: data organized
into categories but not ranked (e.g., gender, ethnicity,
marital status, Dx)
All categories are exclusive & exhaustive
Note: when data are coded for entry into a data
base, they are typically coded (e.g., 1 = male, 2 =
female), but importantly, 1 is not higher or greater
than 2 here)
The concepts of measurement in
research: Ordinal-scales
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(2) Ordinal-scale measurement: can be assigned ranked
categories (e.g., levels of mobility, self-care, daily amount
of exercise)
however, it CAN’t be demonstrated that intervals between
categories are equal in nature (hence, unequal intervals
here)
Sometimes called “ordered metric scales”
All categories are exclusive & exhaustive
E.g., Exercise intensity can be ranked as: 1 = mild
exercise- no SOB, no perspiration; 2 = moderate
exercise, mild SOB, no perspiration, and 3 = strenuous
exercise, SOB with perspiration
The concepts of measurement in
research: Interval-scales
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(3) Interval scales: Distances between
intervals are numerically equal, & assumed
to be a “continuum of values”
However, has absence of a “zero point” so
not a true absolute scale (e.g., temperature,
can’t say that “0” means absence of temp)
The concepts of measurement in
research: Nominal scale
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(4) Ratio-scales: highest form, have all
criteria of previous including mutually
exclusive & exhaustive categories, rank
ordering, equal spacing between intervals &
continuum of values + have “absolute zero”
(e.g.,pulse, wt. & ht.)
Zero pulse means the absence of pulse;
moreover, b/c of absolute zero, one can say
that pulse of 150 is twice as fast as one of 75
beats per minute
Physiological Measures
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Can be either direct or indirect, where direct
are more valid
E.g., measurement of arterial pressure
waveforms through an arterial catheter
provides a direct measurement of blood
pressure, whereas use of stethoscope &
sphygmomanometer provides an indirect
measure
Historical Research:
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Is a systematic approach for understanding past
events through the collection, organization & critical
appraisal of facts
Its goal is to shed light on the past so that it can
guide the present & future
Primary sources: 1st –hand eyewitness accounts
(e.g., diaries, filmed interviewed)
Secondary sources: provide view of phenomenon
from another’s perspective rather than 1st hand
account
Multimethod Component Designs:
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Here, qualitative & quantitative aspects are
implemented as separate & discrete
components for the overall study
These components remain separate &
discrete during data collection, interpretation
& reporting of outcomes
Multimethod Integrated Designs:
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(1) Iterative designs: involve a dynamic in which findings
from one method used to move foreword & refine
alternative method (e.g., one instrument used to
development & refine other instrument)
(2)Nested or embedded designs: one methodological
approach is embedded in the other
(3) Holistic designs: multiply methods are integrated
simultaneously rather than hierarchically
(4) Transformative designs: better suited to theory
building, emphasis is on “blending” different research
traditions to arrive at a better representation of the larger
social context
Epidemiology
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Term derived from Greek “epi” =upon & demos =
people; logos = science
Study of “epidemics”
Investigate how various states of health are
distributed in populations & what environmental
conditions, life-styles or other circumstances are
associated with presence or absence of diseases
Patterns of symptoms often “cluster” in a particular
age group, geographical area or time period (1st clue
in learning what the “cause” is)
Epidemiology: historical roots
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Since antiquity, people have attempted to explain
what “causes” disease/ illness
Often attributed to supernatural events
Hippocrates (460-377 BC) attempted to explain
disease on a rationale basis
In several books (“Airs, Waters & Places, Epidemics
I & II”),he pointed-out that disease is a mass
phenomena & noted that environment & lifestyle are
related to occurrence of disease
Natural History of Disease
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Is a process by which diseases occur & progress in
the human host, involves 3 factors:
(1) Agent: is a factor whose presence causes a
disease or one whose absence causes disease
(chemical, biological)
(2) Environment: refers to all external & internal
conditions & influences affecting the live of living
things (physical, socioeconomic, biological
environment)
(3) Host: human in whom an agent produces disease
Causal relationships:
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Direct causal association: those in which a
factor causes a disease with no other factor
intervening
Causal factor  Outcome
E.g., Tubercule bacillus  Tuberculosis
Causal relationships:
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Indirect causal associations: 3rd intervening
variable, occupies an intermediate stage
between the cause & effect
A B C  D
E.g., Cigarette smoke (A) damages
respiratory epithelium (B); this then increases
susceptibility of epithelium to infection (C); &
this results in chronic bronchitis
The Disease Process
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Occurrence of disease in human host is not a
single event at one point in time, but a
process
“Clinical horizon”: imaginary line dividing the
point where there are detectable signs &
symptoms form that were there are not
Disease process natural Hx. Is divided into 2
board periods: (i) Prepathogenesis &
(ii) Pathogenesis
Prepathogenesis Period:
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(1) Susceptibility:
(a) interrelations of various host, agent, &
environmental factors bring host & agent(s) together
(b) Disease-provoking stimulus is produced in the
known host (remains asymtomatic)
(2) Adaptation: processes are initiated
Research emphasis here is “primary prevention”
(e.g., health promotion/ education, immunizations,
sanitation, removing occupational hazards, dietary
nutrients etc)
Pathogenesis Period:
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(1) Presymptomatic disease/ Early pathogenesis
stage
(a) Interaction of host & stimulus continue after
failure of adaptive response (e.g., immune system is
ineffective)
(b) Stimulus or agent becomes established (e.g., if
infectious agent, increases by multiplication)
(c) Start of tissue & physiological changes
Pathogenesis Period:
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(2) Discernible early lesions stage:
(a) Clinical recognition of disease is possible via lab
or other Dx. Tests to detect early physiological
changes
(b) Pt. develops early symptoms that go unrecogized
as problematic
Research emphasis here is “secondary prevention”
(e.g., early Dx. & screening, prompt Rx., case
finding)
Pathogenesis Period:
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(3) Clinical Disease stage:
(a) Acute illness
(b) Disability
(c) Defect
(d) Chronic state
(e) Death
Research emphasis here is on Rx. to arrest disease
process (e.g., meds, surgery) & “tertiary prevention”
(e.g., rehab. retraining r/t ADL post stroke)
“That’s all folks!”