© 2009 by The McGraw-Hill Companies, Inc. Research Methods in Psychology Introduction.
© 2009 by The McGraw-Hill Companies, Inc. Research Methods in Psychology Observation.
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Transcript of © 2009 by The McGraw-Hill Companies, Inc. Research Methods in Psychology Observation.
© 2009 by The McGraw-Hill Companies, Inc.
Research Methods in Psychology
Observation
© 2009 by The McGraw-Hill Companies, Inc.
Observational Research
Researchers cannot observe• all of a person’s behavior• all people’s behavior
Researchers can observe• samples of individuals• samples of behavior at particular times• samples of different settings and conditions
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Observational Research
Goal of samples• represent larger population of
behaviors people settings and conditions
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Observational Research
Example:• In a typical week, how many hours of
television do you watch? What is the average number of hours for the
class?
• Is this average representative of the number of hours of TV watched by all students on campus? all college students? all people?
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Observational Research
Use data from a sample to represent the population• “generalize” the findings from sample to
population
External validity• extent to which a study’s findings may be
used to describe people, settings, conditions
• beyond those used in the study
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Observational Research
Generalize findings• sample must be representative of population
is sample similar to population? do we know characteristics of entire population?
Psychology studies with college student samples• are psychology students representative of
larger population?
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Sampling Behavior
Extent to which observations may be generalized (external validity)• depends on how behavior is sampled
Two methods• time sampling• situation sampling
Goal: obtain representative sample of behavior
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Sampling Behavior, continued
Time Sampling• choose time intervals for making observations
systematic random
• don’t use time sampling for observing behavior during rare events (e.g., hurricane) event sampling
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Sampling Behavior, continued
Situation Sampling• choose different settings, circumstances,
conditions for observations• enhances external validity• use subject sampling to observe some people
within a situation
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Classification of Observational Methods
Categories based on intervention by researcher• Observation without Intervention• Observation with Intervention
Categories based on methods for recording behavior• comprehensive record• selected behaviors
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Observation without Intervention
Naturalistic Observation• observation in natural (real-world) setting without
attempt to intervene or change situation• use when ethical considerations prevent experimental
manipulation
Goals• describe “normal” behavior, examine relationships
among naturally occurring variables• establish external validity of lab findings
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Observation with Intervention
Most psychological research involves intervention
Three methods in natural settings• participant observation• structured observation• field experiment
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Observation with Intervention, continued
Participant observation• observer is active participant in the natural
setting he or she observes undisguised: people know they’re being observed disguised: people don’t know they’re being
observed
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Observation with Intervention, continued
Problems with participant observation• Reactivity
when people change their usual behavior because they’re being observed
disguised participant observation controls reactivity
• Observers lose objectivity or become too involved in situation
• Observers influence behavior of people they’re observing
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Observation with Intervention, continued
Structured observation• set up (structure) specific situation in order to
observe behavior• used when behavior is difficult to observe as it
naturally occurs• researchers use confederates to structure
situations• problems: when observers don’t follow same
procedures across observations
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Observation with Intervention, continued
Example of structured observation• Simons and Levin (1998): “change blindness”• Web site:
http://viscog.beckman.uiuc.edu/djs_lab/demos.html go to “A subject in a real-world person change event”
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Observation with Intervention, continued
Field Experiment• manipulate independent variable in natural
setting and observe behavior (dependent variable) two or more conditions to compare (IV) often use confederates to create conditions strive for control in natural setting
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Recording Behavior
Comprehensive record• video, audio recordings
Select specific behaviors• checklists, ratings
Method for recording behavior determines how results are• measured, summarized, analyzed, reported
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Recording Behavior, continued
Qualitative Records• Narrative records: complete reproduction of
behavior (video, audio, field notes)• made during or soon after behavior occurs• carefully train observers• advantage: can review record often• disadvantage: costly, time-consuming
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Recording Behavior, continued
Quantitative Records• Selected behaviors• Requires decision regarding how to measure
behavior (e.g., frequency, duration)• checklists, electronic recording and tracking
Measurement Scales• Four levels for quantifying behavior
nominal, ordinal, interval, ratio
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Measurement Scales
Nominal• classify behaviors, events, and characteristics
into categories• checklist examples:
sex (male/female) volunteer to help (yes/no) grade (pass/fail)
• lowest level of measurement
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Measurement Scales, continued
Ordinal• rank-order behaviors and events• 1st, 2nd, 3rd, etc.• example: letter grades on a test (A, B, C, …)
Question: What is the average grade? can’t compute averages using ordinal
measurement
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Measurement Scales, continued
Interval• scale allows researcher to specify distance between
observations on a given dimension• distance between points on scale is equal• example: scores on a test• big advantage: compute means and standard
deviations allows easy summary of groups
• question: does someone who scored 90 on a test know twice as much as someone who scored 45?
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Measurement Scales, continued
Ratio• same as interval, but score of zero is
meaningful• example: time
someone who finished test in 50 min took twice as long as someone who finished in 25 min
• Most psychological measurement: no meaningful score of “0” we don’t recognize concepts such as “zero
memory” or “zero intelligence”
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Measurement Scales, continued
Most psychological measurement• interval scales are assumed• example: rating scale of aggression
1---2---3---4---5---6---7---8---9---10not aggressive very aggressive
• rating scales are treated as interval scales but are more accurately described as ordinal
• Is psychological distance between different points on the scale equal?
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Analysis of Observational Data
Method for analysis depends on• how data are recorded• measurement scale
Two types of analysis• qualitative• quantitative
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Analysis of Observational Data, continued
Qualitative Analysis• comprehensive, narrative records• three steps
code data from narrative record display the data draw and verify conclusions
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Analysis of Observational Data, continued
Example of qualitative data analysis:teacher effectiveness based on videos of teachers and students
(1) Develop coding scheme
classify various teacher and student behaviors
teacher: use of questions, examples, humor
student: ask questions, boredom, note-taking
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Analysis of Observational Data, continued
(2) Display data.
example: Develop a sequence of effectiveness during classroom period in which effective teachers
begin with anecdote
then present an example
then ask a question
then insert humor, etc.
Display this in diagram of nodes from one event to next
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Analysis of Observational Data, continued
(3) Draw and verify conclusions.
example: develop a theory that an effective teacher uses several different types of engagement throughout a class period
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Analysis of Observational Data, continued
Problems with Qualitative Analysis• How to determine if theory is correct?• Validity (truthfulness) of qualitative analyses
often is questioned The data (evidence) to develop theory often are
the same data used to support the theory• Qualitative analyses can be circular
Researchers’ biases can influence which data they examine to support their theory
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Analysis of Observational Data, continued
Quantitative Analysis • selected behaviors• method of data analysis depends on
measurement scale used to record behavior
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Analysis of Observational Data, continued
Nominal• summarize behavior using relative frequency
example: how many people in each category or percentage of people in a category
Interval or Ratio• summarize behavior using central tendency
(mean) and dispersion (standard deviation)
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Analysis of Observational Data, continued
Reliability• refers to consistency• Do two or more observers agree in their
observations? (are they consistent with each other?)
• interobserver reliability example: suppose 2 observers rated “teacher
effectiveness” on a 1–5 scale (not effective–very effective)
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Analysis of Observational Data, continued
• Suppose Observer 1 rated Instructor Z with a “1” Observer 2 rated Instructor Z with a “4”
• Question: Is Instructor Z effective?• Can’t tell because of low interobserver
reliability
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Analysis of Observational Data, continued
Factors that affect interobserver reliability• characteristics of the observers
bored, tired, amount of experience train observers and provide feedback
• clearly define events and behaviors to be observed provide examples
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Analysis of Observational Data, continued
How to assess interobserver reliability• Nominal scale: percentage agreement
number of times 2 observers agree
number of opportunities to agree X 100
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Analysis of Observational Data, continued
• interobserver reliability with nominal scale• example: Is the teacher effective (yes/no)
Observer 1 Observer 2
teacher 1 yes yes agree
teacher 2 yes no disagree
teacher 3 no yes disagree
teacher 4 no no agree
Percent agreement: # of times agree = 2 = .50 X 100 = 50%
# of opportunities 4
50% is low interobserver reliability (< 85%)
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Analysis of Observational Data, continued
• interobserver reliability with interval and ratio scales• correlation coefficient
Obs 1 Obs 2 Obs 1 Obs 2teacher 1 4 3 teacher 11 4 5teacher 2 5 5 teacher 12 4 4teacher 3 2 1 teacher 13 3 3teacher 4 3 3 teacher 14 4 3teacher 5 3 3 teacher 15 5 5teacher 6 4 4 teacher 16 4 4teacher 7 2 2 teacher 17 2 3teacher 8 1 2 teacher 18 2 2teacher 9 1 1 teacher 19 3 2teacher 10 3 3 teacher 20 5 5
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Analysis of Observational Data, continued
correlation between ratings for Observer 1 and Observer 2 = .88
acceptable reliability is correlation greater than .85
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Thinking Critically About Observational Research
Problems in observational research• influence of the observer on behavior• observer bias
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Thinking Critically About Observational Research, continued
Influence of the Observer• Reactivity: people change their usual behavior
when they know they’re being observed• Researchers want to observe people’s usual
behavior• Demand characteristics: people pay attention
to cues and information in the situation to guide their behavior
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Thinking Critically About Observational Research, continued
Controlling reactivity• conceal observer (ethics: privacy issues)• disguised participant observation (privacy)• use indirect (unobtrusive) observation• Adapt participants to observer
habituation desensitization
Reactivity is a potential problem in all psychological research
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Thinking Critically About Observational Research, continued
Observer bias• Observers often have expectations about
behavior example: expectations based on research
hypotheses
• Expectations can lead observers to look at only particular behaviors
• Observer bias: systematic errors in observation that result from expectations also called expectancy effects
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Thinking Critically About Observational Research, continued
Observer bias• potential problem in all research• hard to eliminate• observers must always be aware that they
may be biased• reduce bias by keeping observers “blind” to
aspects of the study: reasons for observations goals of the study hypotheses