Lecture 2 - Theories, hypotheses and variables Flashcards
Define a theory.
Give a few examples of theories in psychology.
Theory -
A formal statement of relations among the observable phenomena.
May contain hypothetical and unmeasurable constructs.
EXAMPLES
- STM and LTM memory
- Attachment theory
- Cognitive dissonance theory
- Triangle theory of love
What are complementary theories?
Complimentary theories -
Same phenomenon at different levels.
e.g.
Pupils contract in bright light
- Functional theory: protects the eye and provides optimal vision.
- Biological theory: retinal signal -> ganglion cells -> sphincter muscles
Both can be correct
What are conflicting theories?
Conflicting theories -
Same level but in different ways.
e.g.
Own-race bias in face recognition
- Genetic theory: born with innate ability
- Developmental theory: developed ability
Define hypothesis.
Hypothesis -
An attempt to organise certain data and specific relationships within a specific portion of a larger, more comprehensive theory.
Generated from a theory.
Can be precisely stated as a relationship between two measurable properties.
Can be falsifiable.
Define null hypothesis.
Null hypothesis -
What must be true if the hypothesis is not true.
e.g.
H1: Swearing reduces pain perception
H0: Swearing has no effect or increases pain perception.
Define a directional hypothesis.
Is it one tailed or two tailed?
Directional hypothesis -
- One tailed
Specifies a specific direction of effect
e.g.
Group A will have higher scores than Group B
H1: A > B
H0: A ≤ B
Define a non directional hypothesis.
Is it one tailed or two tailed?
Non directional hypothesis -
- Two tailed
Direction of difference not specified
e.g.
Group A will have different scores than Group B
H1: A ≠ B
H0: A = B
Define a variable.
Variable -
Something that varies or can be varied.
Must have at least two possible values.
Must be observable and recordable.
Research is all about operationalised variables.
Describe what operationalising means.
Operationalisation -
Each variable needs to be described clearly and unambiguously:
- A description of a construct such that another researcher can produce or measure the same thing.
Typically NOT a definition.
e.g.
An IG test is NOT definition of intelligence but it might be the operationalisation of intelligence for the purpose of the experiment.
Define a dependent variable.
Dependent variable -
A response or behaviour that is measured that may be affected by changes to the independent variable.
- Needs to accurately reflect the performance being assessed.
- Must show good variability over legitimate changes.
(no floor or ceiling effects)
What are ceiling effects?
Ceiling effects -
Occurs when there is some upper limit on a survey or questionnaire and a large percentage of respondents score near this upper limit.
Define validity.
Validity:
The DV measures what is supposed to be measured.
Is a continuum not an absolute.
Define reliability.
Reliability -
Produces consistent measurement in the same situations.
Is a continuum not an absolute.
When should you decide to use more than one dependent variable in your research design?
To check that something else is not also varying.
Define an independent variable.
Independent variable -
What we manipulate as predictors (causes)
