1 1 research methods in ad/pr comm 420 section 8 tuesday / thursday 3:35 pm -5:30 pm 143 stuckeman...
TRANSCRIPT
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Research Methods in AD/PR
COMM 420Section 8
Tuesday / Thursday 3:35 pm -5:30 pm
143 Stuckeman Nan Yu
2007 Fall_COMM 420_Week 4(2) @ NY
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A review
Operational Definitions Variables
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Operational Definition
Answers the question: How do we know?
It translates the concept into simplified terms that can be measured.
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Operational Definition (cont.)
How can an abstract concept be transformed into a concrete variable that can be studied (measured)?
How can it be empirically defined?
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Operational Definition (cont.)
Academic Performance
Final grades
Term papers
Class participation
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Operational definition (cont.)
attention
eye movement
response speed
recall
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Operationalization
Links concepts to variables
Abstract Concepts
Concrete Variables
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Relationships Between Variables
One way to operationalize each concept:
Intelligence (Concept X)
Academic performance (Concept Y)
IQ score (Variable X)
GPA (Variable Y)
Theory
Hypothesis
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IV and DV
independent variable predictor (cause) variable antecedent variable
dependent variable criterion (effect) variable
IQ score (Variable X)
GPA (Variable Y)
Hypothesis
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Intervening Variable Comes in between the IV and DV Usually offers an explanation of why or
how the IV affects the DV E.g., Exposure to TV commercials leads to changes in
attitude towards the advertised product, which in turn lead to product sales.
Exposure to TV
commercials
Changes in attitude towards
advertised product
Product sales
IVDV
Intervening Variable
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Rules
IV can be manipulated or measured. DV are always measured.
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Example
IV: Brand image (manipulated)DV: Purchase intention (measured)
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Example (cont.)
IV: Body type (manipulated)
DV: Perceived body type (measured)
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How do we measure variables?
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Measurements
2007 Fall_COMM 420_Week 4(1) @ NY
length
weight Amount of fluid
temperature
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2007 Fall_COMM 420_Week 4(2) @ NY
How do we measure human behaviors?
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What are measurements?
2007 Fall_COMM 420_Week 4(1) @ NY
The process of assigning numbers to observations according to specified rules.
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Levels of Measurement:Nominal (Categorical)
Nominal (Categorical) Differentiated based on type or category
Very commonly seen in demographic data:
Gender (1=male, 2=female) Political party affiliation (1=democrat,
2=republican, 3=independent).
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Nominal (cont.)
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Nominal (Categorical)
Categories are mutually exclusive
Categories are exhaustive, otherwise they will not represent the variable fully
E.g., One individual case should fit in at least one category
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Levels of Measurement: Ordinal
Ordinal: values can be rank ordered. Social status (1=low, 2=middle, 3=high) Household incomes 1. Less than $ 20,000 2. $20,001 to $30,000 3. $30,001 to $45,000 4. $45,001 to $60,000 5. $60,001 to $80,000 6. $80,001 to $100,000 7. More than $100,000
Ordinal measures provide orders (2 is more than 1), but do not tell how much apart the values in different categories are.
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Levels of Measurement: Interval
If distances between categories are equal, we can say it interval variable.
We assume that the distance between a 1 and 2 is the same as the distance between 2 and 3.
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Levels of Measurement: Ratio
Same attributes as interval variables, plus a meaningful zero point. Height: 6-foot man is twice as tall as a 3-foot
boy. Age: 20-year-old boy is twice as old as a 10-
year-old boy. Temperature: 100 degree is twice as hot as 50
degree Time: 30 minutes is three times as long as 10
minutes. Ration measures mean that a 2 is twice as
much of something.
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Levels of Measurement (cont.)
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Level of Measurements (cont.)
Interval and ratio variables continuous variables. more precise more powerful statistical analysis could be applied
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Scales of Measurement: Likert-type Scale (p.153-154)
Indicate on the scale below, how strongly you agree or disagree with the statement:
Listening to heavy metal music makes one prone to violent acts.
__Strongly agree __Agree __Neutral __Disagree __Strongly disagree
OR
Listening to heavy metal music makes one prone to violent acts.
Strongly disagree Neutral Strongly agree
-4 -3 -2 -1 0 1 2 3 4
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Likert-type scale (cont.)
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Likert-type scale (cont.)
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Semantic Differential (Bipolar)
Similar to Likert-type scales, but involves pairs of attributes based on which the respondent will judge something. E.g., Indicate on the scale below, circling only
one dot, how you feel about the web site you have just seen:
Organized * * * * * * * UnorganizedConfusing * * * * * * * Not Confusing
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Semantic Differential Scales (cont.)
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Thurstone Scales
Generating Potential Scale Items.
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Thurstone Scales (cont.)
Rating the Scale Items.
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Thurstone Scale
Now, you have to select the final statements for your scale. You should select statements that are at equal intervals across the range of medians.
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Open-ended questions
What is your age? How long have you been using
Internet? Provide ideas about how to
develop measurements. Often used during interviews or focus groups.
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Other scales
Guttman Scales Thermometer Scaling Multidimensional Scaling Unobtrusive measures
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Unit of Measurement/Observation
unit of measurement (observation) Smallest unit used for purposes of
observation (e.g., individual, group, news story, etc.).
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Unite of Analysis unit of analysis = Smallest unit used
for data analysis.
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Example E.g., In a survey, we ask (measure)
the annual income of each individual in a household, but in the analysis we might be interested in the average income per household.
What is the unit of observation/analysis in this case?
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Decisions in the Measurement Process
Any existing measures of the variables of interests?
What is the unit of observation (individuals, social groups, stories, etc.)?
Who measures (self-report, other-report, researcher, etc.) whom (sampling)?
What levels/types of measurements do you use (e.g. interval? Likert-type)?
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Measurement Error
All measurements are subject to error Two types of measurement error:
Systematic error (due to instrument calibration)
Constant and predictable Random error
Erratic and unpredictable
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Pilot test (pre-test) A test before the formal research is conducted
Test the stimulus Test the measurement instruments Eliminate potential problems Reduce predictable errors
It’s like a mini test to make sure everything goes well as you expected. The sample could be a lot smaller than the actual sample. But you can not include the same person in both.
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In-class Demo
Please go to this website http://www.personal.psu.edu/mbo1/fo
rms/survey1/survey1.html Down load the file “in-class demo”
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In-class Demo (cont.)
Click and answer all questions that are on the questionnaire.
Identify the level of measurement of each PART
Submit your answers to ANGEL (week 4, drop box for in-class Demo)