Unit 2: Theories and Measurement Flashcards
Phenomenon
An established answer to a research question.
A general result that has been observed reliably in a systematic empirical research.
Ex: Fundamental attribution error
People tend to explain others’ behaviour in terms of their personal characteristics as opposed to the situation they are in. Varies between cultures (more in N America than Asia)
Ex: Bystander effect; the more people who are present at an emergency situation, the less likely it is that any one of them will help.
Ex: Social facilitation; while being watched by others, people perform better on highly practiced tasks
Ex: Social inhibition; while being watched by others, people perform worse on relatively unpracticed tasks
Replication
When a study is conducted again to ensure it produces the same results. Can be done exactly as the previous study, or with modifications
Theory
A coherent explanation or interpretation of one or more phenomena
Goes beyond the phenomena by explaining variables, structures, processes, functions, or organizing principles that have not been observed directly
Ex: Zajonc’s drive theory; being watched creates physiological arousal, which increases dominant response. So increase in correct highly practiced behaviour. Explains social facilitation and social inhibition (decrease in correct display of unpracticed behaviour)
Perspective
A broad approach to explaining or interpreting phenomena
More general than a theory
Ex: Biological perspective explains in terms of genetics or the nervous system
Model
A precise explanation or interpretation of phenomena
Can be expressed in terms of equations or biological processes
Theoretical framework
Provides the context applied to understanding a phenomenon; guides the interpretation of the observations
Can be as broad as a perspective, or as precise as a model
Basic purposes of scientific theories
- Organize phenomena; theories are good or useful when they coherently explain the results of many studies in a clear and concise way
- Predict what will happen in new situations; help physicians make informed decisions about treatment
- Help generate new research; even an inaccurate theory can generate new and interesting research questions, produce new results, and help to refine the theory
Types of dimensions that differ in theories
- Formality
- Scope
- Theoretical approach
Functional theories
Explain psychological phenomena in terms of their function or purpose. Explain the “why”
Ex: Cutting produces a short-term reduction in the intensity of negative emotions
Ex: Evolutionary psychology - human behaviour has evolved to solve specific adaptive problems
Mechanist theories
Focus on specific variables, structures, and processes, and how they interact to produce the phenomena. Explain the “how”
Identify a mechanism/explanation of phenomena and give context to when it happens or how intense it is
Ex: Social facilitation/inhibition
Stage theories
Provide organization without using functional or mechanist explanations
Specify a series of stages that people pass through as they develop or adapt to their environment
As people pass through the stages, they integrate their outcomes from previous stages to help them succeed in the next stage
Can’t revert to previous stages
Typologies
Provide organization by categorizing people or behaviour into distinct types
Ex: Basic emotions, types of intelligence, personalities
Unlike stage theories, people do not progress through typologies in any order, or do not progress through them at all
Nominal scales
Descriptive scales; simply names or categorizes responses with no inherent numerical value and do not imply any ordering among the responses
The only form of central tendency that applies is mode
Ex: Favourite colour, religious affiliation
Ordinal scales
Ordered scales; allow comparisons of the degree to which two individuals rate the variable
The differences between adjacent scale
values do not necessarily represent equal intervals
Ex: How satisfied a customer is (somewhat satisfied, very dissatisfied, etc)
Interval scales
Numerical scales in which intervals have the same interpretation throughout
Do not have a true zero point
Ex: temperature in Celsius or Fahrenheit (zero is arbitrary)
Ratio scales
Interval scale with the additional property that its zero position indicates the absence of the
quantity being measured
Has the combined qualities of nominal, ordinal, and interval scales
Ex: temperature in Kelvin (zero = absolute zero), height in m, weight in kg, money
Reliability
The ability to consistently produce a given result
Any instruments or tools used to collect data do so in consistent, reproducible ways
Used to evaluate a method of measurement
Ex: Kitchen scale measures 100g of flour 5 times in a row, but is not calibrated correctly
Validity
The extent to which a given instrument or tool accurately measures what it’s supposed to measure
Ex: Kitchen scale measures 100g of flour, and the amount is actually 100g
Psychological construct
A label to describe a complex set of behaviours, internal processes and how they relate to other variables
Cannot be observed or measured directly; are often tendencies (of behaviour, thinking, or feeling) and involve internal processes
Ex: Intelligence, self-esteem, depression
Ex: Big 5 personality of neuroticism (negative emotion, remains stable over time, genetic influence)
Operational definition
A definition of a variable in terms of precisely how it is to be measured
A variable can have multiple definitions
Ex: Self-report, behavioural, or physiological measures
Converging operations
When multiple operational definitions of the same psychological construct are used, either within a study or across studies
The various operational definitions are “converging” or coming together on the same construct
Correlational design
When scientists passively observe and measure phenomena. Involves exactly 2 variables, to identify patterns of relationships. Cannot infer what causes what.
In comparison, experiments involve intervention and change behaviour
Why can psychological theories be falsified but not proven?
The theory can be supported by evidence, but conclusions provide confirmation, not proof (unlike a mathematical proof). As more evidence is obtained, conclusions are refined.
Falsification is possible because observations can provide evidence that disproves a theory. Ex: observing a person without exactly five toes on each foot.
Parsimony
A theory should include only as many concepts as are necessary to explain or interpret the phenomena of interest.
A parsimonious theory organizes phenomena more efficiently and simply
Also known as Occam’s razor.
Formality (in theories)
The extent to which the components of the theory and the relationships among them are specified clearly and in detail
Informal theories - easier to create/understand, predictions are less precise, more difficult to test
Formal theories - more difficult to create/understand, more precise, easier to test
Scope (in theories)
The number and diversity of the phenomena they explain or interpret
Broad scope - organize large number of phenomena, are less precise; Freud’s theories tried to cover all of human behaviour
Narrow scope - organize small number of closely related phenomenon, are more precise
Theoretical approaches
Theories in psychology vary widely in the kinds of theoretical ideas they are constructed from
Ex: Functionalist, mechanist, and stage theories
Hypothetico-deductive method
- Starts with a phenomenon
- Constructs a theory to explain it, or chooses an existing theory to use
- Makes a prediction about phenomenon in a new situation (hypothesis)
- Conducts empirical research to test prediction
- Revises theory using new results
Matches with scientific model and, when combined with it, produces “theoretically motivated” or “theory-driven” research
Measurement
Assignment of scores to individuals so that the scores represent some characteristic of the individual
Does not require instruments or procedures
Requires some systematic procedure for assigning scores so that the scores represent the characteristic of interest
Self-report measures
When a variable is operationalized by participants’ self-report of thoughts, feelings, actions
Ex: Rosenberg Self-Esteem Scale
Behavioural measures
When a variable is operationalized by observing and recording participants’ behaviour
Ex: memory recall in a lab setting, aggression in a natural setting
Physiological measures
When a variable is operationalized by measuring participants’ physiological processes
Ex: heart rate, blood pressure
Test-retest reliability
The extent to which a construct that’s assumed to be consistent across time actually is consistent across time
Ex: Intelligence
How to assess it: test-retest correlation
Internal consistency
A kind of reliability that involves a multiple-item measure (such as a survey) and the consistency of responses across all items
The questions on the survey are intended to reflect the same underlying construct. Therefore, an individual’s scores across all items should correlate with each other
Ex: Rosenberg Self-Esteem Scale - If a participant says they are a person of worth, then they should also agree they have a number of good qualities
How to assess it: split-half correlation
Test-retest correlation
Used to assess test-retest reliability of a construct that is assumed to be consistent over time
- Use measure on one group at one time, then again on the same group at a later time
- Use correlation between 2 sets of scores.
- r = .80 or higher indicates the measure has good reliability
Split-half correlation
Used to assess internal consistency (a form of reliability)
- Items are divided into 2 sets (first and second half, or odd and even items)
- Compute a score for each set and correlate the scores
- r = .80 or higher indicates good internal consistency
Cronbach’s a (alpha)
A statistic to assess internal consistency
Conceptually, it is the mean of all possible split-half correlations for a set of items.
r = .80 or higher indicates good internal consistency
Interrater reliability
In an experiment, how consistent different observers are with their judgements (i.e. researchers who are rating participant behaviour)
Ex: 2 observers recording aggressive behaviour from the same participants should have ratings that correlate with each other
Quantitative scores are often assessed using Cronbach’s a (alpha)
Categorical scores are often assessed using Cohen’s k (kappa)
Face validity
The extend to which a measurement method appears “on its face” to measure the construct/variable of interest
A weak measure of validity because it’s based on intuitions about human behaviour, which are often incorrect
Criterion validity
The extent to which a person’s score on a measure is correlated with other criteria that one would expect them to be correlated with
Ex: A new measure of test anxiety would have good criterion validity if it has a negative correlation to exam scores (high anxiety is expected to result in lower exam scores)
Ex: concurrent, predictive, and convergent validity
Content validity
The extent to which a measure “covers” the construct of interest
Ex: Conceptual definition of test anxiety includes nervous feelings and negative thoughts. The measure should include items about feeling nervous and thinking negatively
Concurrent validity
A type of criterion validity. When the criterion is measured at the same time as the construct
Predictive validity
A type of criterion validity. When the criterion is measured at some point in the future
It is “predictive” because scores on the construct measure predict the outcome of the criterion measure
Convergent validity
A type of criterion validity. When the criterion used is another existing measure of the same construct
Discriminant validity
The extent to which scores on a measure are NOT correlated with measures of conceptually distinct variables
Ex: Self-esteem is a general attitude that is fairly stable over time. Mood is variable, how one feels right now. If a new measure of self-esteem does not correlate with mood, then it would demonstrate a concept that is conceptually distinct from mood (high discriminant validity)
