Physical Traces

Research Methods in Psychology
Unobtrusive Measures of
Unobtrusive Observational Methods
 Learn about behavior by looking at
evidence of people’s past behavior
 Nonreactive
• people can’t react to being observed because
they’re no longer present
The Multimethod Approach
 Unobtrusive measures contribute to
multimethod approach to understanding
behavior and mental processes
 Multimethod
• Use a variety of measures to examine
research questions:
 direct observation
 surveys
 unobtrusive measures
The Multimethod Approach, continued
 Research findings based on a single
method may be biased because of
• characteristics of measurement process
• reactive measurement
 Advantage of using multiple methods
• converging evidence for a phenomenon
across different methods → stronger
Two Unobtrusive Observational Methods
 Physical traces
• remnants, fragments, and products of past
 Archival records
• public and private documents that describe
activities of
 individuals
 groups (e.g., institutions, government)
Physical Traces
 Physical trace measures are obtained
• people who are “observed” are not present
when the data are collected
 Two types
• use traces
• products
Physical Traces, continued
 Use traces
• evidence that remains from the use (or
nonuse) of an item
• example: beverage containers in campus
recycling bins (e.g., water, soda, juice, coffee)
 What do these containers tell us about the health
habits of students on campus?
Physical Traces, continued
 Use traces are classified as natural or
controlled (planned)
• Natural-use traces
 produced without any intervention by the
 example: analyze amount of highlighting in
students’ textbooks
• What information does this provide about students’
studying? About what is learned?
Physical Traces, continued
• Controlled-use traces
 produced with some degree of intervention or
manipulation by the researcher
 example: place small glue seals between some
pages of textbooks prior to their purchase, then
analyze which pages are unsealed
• What does this tell us about students’ studying?
Physical Traces, continued
 Products
• creations, constructions, or other artifacts of
earlier behavior
• examples
 television programs such as Howdy Doody,
Sesame Street, Mister Roger’s Neighborhood,
Power Rangers, Pokemon, Teletubbies, Wiggles
 What do children’s TV programs tell us about our
Physical Traces, continued
 Problems and Limitations
• Valid measures of behavior?
 many inferences may be possible based on
physical evidence
• Biases in physical traces?
 biases can exist in how physical traces are created
or how they survive
• Use multimethod approach
 collect supplemental evidence
 look for converging evidence for a conclusion
Archival Data
 Archival records
• public and private documents of individuals,
institutions, governments, and other groups
• two types
 running records (e.g., your transcript)
 records of specific events (e.g., your graduation)
• data from archival records are nonreactive
 people’s behavior is observed indirectly
Archival Data, continued
 Archival data are used to
• test hypotheses as part of a multimethod
• test the external validity of laboratory findings
 do findings generalize to a real-world setting?
• test hypotheses about past behavior
• assess the effect of a natural treatment
Archival Data, continued
 Natural treatments
• naturally occurring events that impact society
and individuals
• examples
 societal level: drastic changes in stock market,
acts of terrorism, election of new president
 individual level: death of a parent, divorce,
• use archival data to examine effects of natural
treatments on people’s behavior
Content Analysis
 Content analysis
• process of making inferences based on
objective coding of archival data
• two types
 quantitative: classify events and behavior into
categories to count their frequency of occurrence
 qualitative: make subjective judgments about the
content in an archival record
Content Analysis, continued
 Three steps
• Identify a relevant source
 Choose archival records that will provide relevant
information to answer the research question
• Sample selections from the source
 Goal: obtain a representative sample
• Code units of analysis
 Use precise operational definitions and appropriate
units of measure
Archival Data, continued
 Problems and limitations
• Selective deposit
 occurs when some information is selected to be
included in archival record, but other information is
 examples:
• doctors don’t “chart” all of the information that a patient
provides, only what they consider most important
• politicians speak “on the record” or “off the record”
Problems and Limitations, continued
• Selective survival
 occurs when information is lost or missing from an
archival source
 examples:
• when students drop a course within a certain time period,
the record of their enrollment is dropped from the
• photos may be lost from albums or yearbooks (e.g.,
following divorce)
Problems and Limitations, continued
• Spurious relationship
 exists when evidence falsely indicates two or more
variables are related
 occurs because of
• statistical problems or inadequate analysis
• coincidence, as when a correlation between two
variables can be attributed to a third variable
 example:
• ice cream sales and crime rates are positively correlated
 does eating ice cream cause crime?
 does crime cause people to eat ice cream?
 3rd variable: temperature
Ethical Issues and Unobtrusive Measures
 Unobtrusive measures
• help psychologists meet ethical goals of
 understanding of behavior
 condition of individuals and society
• have lower risk to participants
 very favorable risk/benefit ratio
• lower cost of the research because the data
already are collected