Methods
Methods 1
Intuition - when you believe you know something because it feels so
Pure Observation - take your own senses to observe the world in a particular way
Authority - world works in a particular way because an expert says so
Problem with “pure” observation
Can’t be perceived/ not possible
Not always true/ misperception
Ex. Visual illusions
Own observation can change overtime
People disagree on what they are experiencing
TERMS
Science
Community of people following agreed rules and policies for observing, predicting, and explaining some part of our world
Scientific method creates:
Theories
Possible explanations for why or how something works
Hypothesis
Predictions about what should happen in a specific situation
Studies / experiments
Observational tests of a hypothesis by creating or finding situations in which the hypothesis should hold true
Universality
When formulating a hypothesis or theory, the number of people we believe it applies to
Science: assumptions
Human nature can be studied through scientific testing
Some parts of human are fixed, predicable, and universal
Generalization are made about people as a group, not about specific individuals
Science is not the only way of knowing things, just primary method used in psychology
Scientific observation
Scientific skepticism
Should not be attached to a specific theory or hypothesis
Peer review
Send your conclusions for review from other scientists
Replication
Multiple studies done the same way should generate similar data
Falsifiable Hypothesis
Make inflexible predictions that can be shown to be false with observation
Scientific observation
To deal with impossibility of observation we develop new tools
To deal with unreliability of observation
Openness: all data should be publicly available
Double-Blind experiments: neither participant nor person collecting the data should be aware of what the hypothesis is
Scientific process
FULL CIRCLE (definitions are below)
Hypothesis → Operationalize → Measure → Analyze and Interpret → Report
Operational Definition
A description of a psychological property in measurable observable terms
Ex. stage fright
Measure heart rate (good one)
# of times person say “im so nervous” (not the best)
Measure
Instrument: anything that measures the operational definition
Heart rate monitor:
Measure beats per min
How hard the heart is beating
Construct validity: measure what it's supposed to measure
Reliability: it gives similar measurements each time it is used
Power/ Sensitivity: detect small differences in the measure (fine grains of differences)
Ex.
Questionnaires, computer tasks, physiological measures
Definition + instruments = data - a collection of measurements
Methods 2
Study Design/ Methods: used in psychology to observe and interpret data
Naturalistic Observation =: collecting data in the real world by simply observing in a natural environment
Ex. looking at child development at a school
Case-Studies = collecting data on one or few unique individuals
Ex. individuals who have brain damage
Correlational Studies = estimated numerical prediction between 2 measured variables
Ex. study of age and political party
Estimate what age affiliates with a certain political party
Types of correlation and ex
Positive correlation (more sleep associated with more stress)
No correlation (more sleep has no association with stress)
Negative correlation (more sleep associated with less stress)
Problem:
Directionality problem: correlation of A might cause B or B might cause A
Third Variable Problem: third, unmeasured variable C (confound)
Coincidence: some things drawn together through luck and random
Spurious correlation: strongly correlated variables that we know are not casually related, and correlate because of confounds or coincidence
Experiments: one variable is manipulated by an experimenter to see its casual effect on another
Experimental group: do the task that is “abnormal” (ex. Deny sleep)
Control group: do the task that is “normal” (ex. Sleep normally)
Independent variable (IV): the variable manipulated and predicted to have a casual effect
Dependent variable (DV): the variable mature, and predicted by to caused by the IV
Random selection/ sampling participants should be chosen from the study randomly from the whole general population
Random assignment: participants are put into the IV groups randomly
Solution to directionality: you control the direction by choosing which variable you manipulate and which you measure
Solution to third-variable(s): two groups will be theoretically identical in every third variable, so only difference will be from the manipulation you made
Solution to coincidence: studies are replicated by other researchers multiple times to make sure the result wasn’t by chance
2.1 Empiricism: How to know stuff
Empiricism -accurate knowledge of the world can be acquired by observation
Scientific method -procedure for using imperial evidence to establish facts
Also tells us the truth about the world is to:
1) develop a theory
2) derive a falsifiable hypothesis
3) test that hypothesis by observing the world
Theories -explanations of natural phenomena (idea about how something works)
Hypothesis -falsifiable prediction made by a theory
Falsifiable -using the scientific method to evaluate its accuracy
Empirical method -set of rules and techniques for observation
Why: because human eyes may see inaccurately
Method -technologies that enhance the powers of the senses
Human beings have three qualities that make them more difficult to study:
Complex (human body is complex with 100 billion interconnected neurons)
Variable (no one feels exactly the same thing under exactly same circumstances)
Reactive (people tend to think, feel, act different when observed or not
Methods of observation -allow them to discover what people do
Methods of explanation -allow them to discover why people do it
2.2 Methods of Observation: Discovering What People Do
Measurement (two steps)
1) Operational definition -description of a property in measurable terms
Ex. define happiness as “the amount of dopamine in a person’s brain” or “amount of smiles in an hour”
In an operational definition, one key feature is:
Construct validity = specified operation are generally considered good indicators of the specified properties
Ex. using smiles to define happiness would seem logical but not eating no. of chocolates
2) In a good detector, two key features are:
Power = detector’s ability to detect the presence of differences or changes in the magnitude of a property
Reliability = detector’s ability to detect the absence of differences or changes in the magnitude of a property
Demand characteristics -aspects of observational setting causing people to behave as they think someone else wants or expects
Ex. friend ask you if they are pretty = most likely say yes
To avoid demand characteristics, there are three techniques:
Naturalistic Observation -technique to gather info unobtrusively observing people in their natural environments
Privacy and Control -can’t be identified as the authors of their action, respond privately
Unawareness -people are are being observed are unaware of the true purpose of the observation
Fast VS Slow Rat Study
Psychology students measured how quickly rats learned a maze. Some students were told their rat was bred to be a slow learner, others a fast learner, though all rats were identical. Students expecting slow learners reported an average time of 3.47 minutes, while those expecting fast learners reported 2.35 minutes. The results reflected the students’ expectations rather than reality, for two reasons:
Expectations can influence observations
Expectations can influence reality
This is called:
Observer bias = tendency for observers’ expectations to influence both what they believe they observed and what they actually observed
To avoid this, they use techniques (most common)
Double blind study = study in which neither the researcher nor the participant knows how the participants are expected to behave
Description
Population = complete collection of people
Sample = partial collection of people drawn from a population
Frequency distribution -graphic representation showing the number of times that the measurement of a property takes on each of its possible values
Normal distribution -mathematically defined distribution in which the frequency of measurements is highest in the middle and decreases symmetrically in both directions
Central tendency -descriptive statistics are statements about the value of the measurements that tend to lie near the centre or midpoint of the frequency distribution
Mode - value of the most frequently observed measurement
Mean -average value of all measurements
Median -value in the middle
Variability: how wide is the distribution
Variability = tells us how much the measurements differ from each other or roughly how “wide” the distribution is
Range = value of the largest measurement in a frequency distribution minus the value of the smallest measurement
Standard deviation = how each of the measurements in a frequency distribution differs from the mean