Hindsight Bias
the tendency to believe after leaving an outcome, that one would have foreseen it. ( I knew it all along)
Theory
an explanation using an integrated set of principles that organize observations and predict behaviors or events
Hypothesis
a testable prediction, often implied by a 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 finding can be reproduced
Case Study
a descriptive technique in which one individual or group is studied on depth in the hope of revealing universal principles
Naturalistic Observation
a descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation
Survey
descriptive technique for obtaining the self-reported or behaviors of a particular group, usually by questioning a representative, random sample of the group
Sampling Bias
a flawed sampling process that produces an unrepresentative sample
Populations
all those in a group being studied from which samples may be drawn
Random Sampling
A sample that fairly represents a population because each member has an equal chance of inclusion
Correlation
measure of the extent to which two factors vary together, and thus of how well either factors predict the other
Correlation Coefficient
a statistical index of the relations between two things (from -1.00 to 1.00)
Variable
anything that can vary and is feasible and ethical to measure
Scatterplot
a graphed cluster of dots, each of which represents the values of 2 variables. The slope of the point suggest the direction of the relationship between the 2 variables. The amount of scatter suggests the strength of the correlation. ( little scatter indicates higher correlation)
Illusory Correlation
perceiving a relationship where none exist or perceiving a stranger -than- actual - relationship
Regression toward the mean
the tendency for extreme or unusual scores or events to fall back (regress) toward the average
Experiment
a research method in which an investigator manipulates one or more factors (independent variable) to observe the effect on some behavior or mental process ( the depend variable ) by random assignment of participants, the experiment aims to control other relevant factors.
Experimental group
in an experiment, the group exposed to the treatment, that is, to one version of the independent variable
Control group
in an experiment, the group not exposed to the treatment: contrast with the experimental group and serves as a comparison for evaluating the effect of the treatment
Random Assignment
assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups
Double-Blind procedure
A Double-Blind procedure is an experimental technique where both the research participants and the research staff are unaware of whether the participants have received the treatment or a placebo. This method is commonly used in drug-evaluation studies.
Placebo
experimental results caused by expectations alone;any effect on behavior caused by the administrator of an inert substance or condition which the recipient assumes is an active agent
Independent variable
in an experiment, the factor that is manipulated; the variable whose effect is being studies
Confounding variable
a factor other than the the factor being studies that might influence a study’s result
Dependant Variable
in an experiment the outcome that is measures; the variable that may change when the independent variable is manipulated
Validity
the extent to which a test or experiment measures or predicts what is supposed to
informed consent
giving potential participants enough information about a study to enable them to choose whether they wish to participate
Debriefing
the postexperimental explanation of a study including its purpose and any deceptions to its participants
Descriptive statistics
numerical data used to measure and describe characteristics of groups. Including measures of central tendency and measures of variation
Histogram
a bar graph depicting a frequency distribution
Mode
the most frequently occuring scores in a distribution
Mean
the arithmetic average of a distribution obtained by adding the scores and then dividing by the number of scores
Median
the middle score in a distribution; half the score are above it and half are below it
Skewed distribution
a representation of scores that lack symmetry around their average value
Range
the difference between the highest and 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 describes the distribution of many types of data;most scores fall near the mean and fewer near the extremes
Inferential Statistics
numerical methods used to determine whether research data support a hypothesis or whether results were due to chance.
Statistical significance
a statistical statement of how likely it is that an obtained result occurred by chance