Ch 2 - Methods in Psych

Scientific Method

a set of principles about the appropriate relationship between ideas and evidence (taking an idea/thought and finding evidence for it)

Theory

a hypothetical explanation of a natural phenomenon

Hypothesis

a falsifiable prediction made by a theory

Empirical Method

a set of rules and techniques for observation

Subjective

own personal feelings about things

Objective

measurable things

Operational Definition

how we define any given variable (by a specific and precise procedure)

Measure

a device that can detect the condition to which an operational definition refers

Measure: Validity

actually measuring what we want to measure

Measure: Reliability

tendency of a measure to produce the same measurement whenever it's used to measure the same thing (consistency)

Measure: Power

ability of a measure to detect the concrete conditions specified in the operational definition (measure good enough? sample size large enough?)

Demand Characteristics

aspects of an observational setting that cause people to behave as they think someone else wants or expects

Observer Bias

expectations can influence observations and influence perceptions of reality

Naturalistic Observation

technique to gather information by unobtrusively observing people in their natural environment

Double-Blind Procedure

observation whose true purpose is hidden from both the observer and the subject

Positive Correlation

both variables increase or decrease together (variations in both variables in synchronized)

Negative Correlation

variables move in opposite directions

Natural Correlation

a correlation observed in the world around us

Third Variable Problem

a casual relationship between two variables cannot be inferred from the naturally occurring correlation between them because of the ever-present possibility of third-variable correlation

Manipulation

the creation of an artificial pattern of variation in a variable in order to determine its causal powers

Independent Variable

variable that is manipulated (changes)

Dependent Variable

the variable that is measured (outcome)

Random Assignment

a procedure that uses a random event to assign people to the experimental or control group

Experimental Group

the group of people who are treated in a particular way in an experiment

Control Group

the group of people who are not treated in the particular way that the experimental group is treated in an experiment

Self Selection

a problem that occurs when anything about a person determines whether he or she will be included in the experimental or control group

Population

a complete collection of participants who might possibly be measured (N)

Sample

a partial collection of people drawn from a population (n)

Random Sampling

a technique for choosing participants that ensures that every member of a population has an equal chance of being included in the sample

Case Method

a method of gathering scientific knowledge by studying a single individual

Code of Ethics

informed consent, freedom from coercion, protection from harm, risk-benefit analysis, deception, debriefing, and confidentiality