Chapter 2 Flashcards
Empiricism
The belief that accurate knowledge can be acquired through observation
Scientific method
A procedure for finding facts by using empirical evidence
A theory
A hypothetical explanation for a natural phenomenon
The rule of parsimony
The simplest theory that explains all the evidence is the best one. (To start with at least)
Hypothesis
A falsifiable prediction made by a theory
Empirical method
A set of rules and techniques for observation
An instrument
Anything that can detect the condition to which a operational definition refers.
What does a good definition need?
Validity, the extent to which a concrete event defines a property
What does a good instrument need?
Reliability - the tendency for an instrument to produce the same measurement when measuring the same thing.
Power - an instruments ability to detect small magnitudes of the property.
Demand Characteristics
The aspects of an observational setting that cause people to behave as they think others want or expect
Naturalistic Observation
A technique to gather info by unobtrusively watching people in their natural habits
Ways to avoid demand characteristics without naturalistic observation?
Privacy and control - Let people respond privately or anonymously, or record things hard to control (eye dilation)
Unawareness - have the people unaware of what they’re being observed for.
Observers bias
Observers will unconsciously lean towards what they expect to observe.
Double-blind observation
Both the observer and person observed don’t know the true purpose of the observation
Frequency distribution
A graphic representation of measurements arranged by the number of times each measurement was made
Normal distribution
A mathematicaly defined distribution in which the frequency of measurements is highest in the middle and decreases symmetricaly on both sides
(A bell curve)
Correlation
When variations of one variable relates to the variations of another
Correlation coefficient
A mathematical measof both the direction and strength of a correlation
Third-variable correlation
Two variables are only connected because they are both connected to a third.
Third-variable problem
A relationship between two variables cannot be inferred because of the possible of a third connected variable
Experiment
A technique for establishing the casual relationship between variables
3 Essential Characteristics of Experiments
Manipulate one variable
Did something change in the other variable?
Control for other possibly interfering factors
Independent variable
The variable that is manipulated
Experimental group
The group of participants who are exposed to a particular manipulation
Control group
The group of participants that are not exposed to manipulation
Dependant variable
The variable that is measured
Self-selection
A problem that occurs when something about a participant dictates whether they will be in the experimental or control group.
Random assignment
Procedure that lets chance assign participants to the experimental or control group
Internal validity
An expirement has it if it can effectively establish causal relationships
External validity
A experiment has this when variables have been defined in normal, typical, or realistic ways
Sample
A partial collection of people drawn from a population
Random sampling
A technique for choosing participants where everyone in a population has an equal chance of being chosen
When participants are randomly selected, the sample is said to be…
Representative of the population
Direct replication
An experiment that uses the same procedures as a previous experiment but with a new sample
Bidirectionality problem
Does X cause Y or does Y cause X?
