Theory
explains behaviors or events by offering ideas that organize what we have observed. An explanation using an integrated set of principles that organizes observations & predicts behaviors or events; can be proven or disproven
Hypothesis
testable predictions; often implied by the theory
Operational Definition
a carefully worded statement of the exact procedures (operations) used in a research study
Replication
repeating the essence of a research study, usually with different participants in different situations, to see whether the basic findings extends to other participants & circumstances
Descriptive Methods
describes behaviors; often through case studies, surveys, or naturalistic observations
Correlational Methods
associates different factors
Experimental Methods
manipulates factors to discover their effects
Case Study
descriptive technique in which one individual or group is studied in depth in hope of revealing universal principles
Naturalistic Observation
watching & recording the natural behavior of many individuals
Survey
descriptive technique for obtaining the self-reported attitude or behaviors of a particular groups , usually by questioning a representative, random sample of the group
Population
all those in a group being studied from which sample may be drawn
Random Sample
a sample that fairly represents a population because each member has an equal chance of inclusion
Correlation
a measure of the extent to which two factors vary together, & thus how well either factor predicts the other
Correlation Coefficient
a statistical index of the relationship between two things
Scatterplot
graphed cluster of dots which represent values of two variables slope suggests direction of relationship. Amount of scatters suggest strength of correlation. + slope = positive direct proportion, 0.0 = no correlation, - negative direct proportion
Illusionary Correlation
remembering more confirming things than disconfirming things
Regression Towards the Mean
tendency for extreme or unusual scores or events to fall back (regress) towards the average
Experiment
research method where one manipulates 1+ factors to observe effect a behavior or mental process
Experimental Group
groups in an experiment exposed to treatment, one version of the independent variable
Control Group
group in an experiment not exposed to treatment/independent variable serves as comparison between groups
Random Assignment
assigning people to control or experimental group by chance to minimize preexisting differences
Double Blind Procedure
experiment procedure where neither the participant nor the researcher knows who is in control or experimental group
Placebo Effect
experimental results caused by expectation alone; when someone improves because they think they are getting the experimental thing
Independent Variable
factor that can be/is manipulated; variable whose affect is being studied
Confounding Variable
factor other than the independent variable that might produce affect
Dependent Variable
outcome that is measured; variable may change when independent variable changes
Theoretical Principles
principles/ideas - not the actual findings to help explain everyday behaviors
Informed Consent
giving potential participants enough information about a study to enable them to choose whether they wish to participate
Debriefing
the post-experimental explanation of a study, including its purpose and any deceptions to its participants
Descriptive Statistics
summary statistics that quantitatively describe or summarize feature from a data set
Mode
most frequent value in a data set
Mean
the arithmetic average of a distribution obtained by adding the scores & dividing them by the # of scores
Median
the middle score in a distribution; half the scores are above it & half the scores are below it
Measures of Central Tendency
single score that represents a whole set of scores; neatly summarize data
Range
the difference between the highest & lowest scores in a distribution
Standard Deviation
a computed measure of how much scores vary around the mean score
Normal Curve
a symmetrical, bell-shaped curve that describe the distribution of many types of data; most scores land near the mean
Inferential Statistics
use of measurements from the sample of subjects in the experiment to compare the treatment groups & make generalizations about the large population of subjects
Statistical Significance
a statistical statement of how likely it is that a obtained result occurred by chance