r

Symbol used for the Pearson-product moment correlation (correlation coefficient)

Random Assignment   

Assigning subjects to experimental groups based on chance.

Random Sample   

A group of subjects representing the population who are selected through chance.

Range  

the difference between the highest and lowest score in a distribution (often 1 is added to the result when computing statistics to allow for the 0.5 on either end lost due to rounding).

Rank-Ordered Array

A table consisting of data in order of highest to lowest or lowest to highest where each data is given a numbered rank depicting it's difference from the highest or lowest score

Ratio Scale

Any scale of measurement possessing magnitude, equal intervals, and an absolute zero 

Rational Emotive Therapy   

A Cognitive Therapy based on Albert Ellis' theory that cognitions control our emotions and behaviors; therefore, changing the way we think about things will affect the way we feel and the way we behave.

Rationalization    

A defense mechanism where one believes or states an acceptable explanation for a behavior as opposed to the real explanation.

Raw Data

The initial data gathered that has not yet been graphed, organized, or analyzed.

Reaction Formation   

A defense mechanism where unacceptable impulses are converted to their opposite.

Reality Principle

According the Freud, the attempt by the ego to satisfy both the id and the superego while still considering the reality of the situation.

Recency Effect   

The tendency to remember the last bit of information due to the shorter time available for forgetting.

Reconstruction  

Tendency to fill in the gaps in our memory and often believe these represent true memories.

Referent Power  

Power given to an individual due to respect and/or desire to be similar to that individual.

Reflection

A therapeutic technique in humanistic therapy where the feelings and thoughts of the client are reflected or reworded back to the client to assist in understanding them.

Regression Analysis

Used with a correlation to determine a regression equation that predicts or estimates a persons score on one variable if the other is known.

Rehearsal   

Repeating information in order to improve our recall of this information.

Reinforcer   

Anything that follows a behavior that increases the chances of that behavior occurring again.

Regression   

A defense mechanism where one reverts to an earlier stage of development.

Reliability   

A statistical measure of a tests consistency, or ability to result in similar scores if given repeatedly.

Reliability Coefficient

The correlation coefficient is called the reliability coefficient when a correlation is used to determine or estimate reliability.

Replication

The strength of a research study is only as good as its ability to be replicated. In other words, if a study has significant results but can not be done again, it is difficult to assess whether it was a good study or a result of error.

Representative Sample

A sample or subgroup of the population that possesses the same characteristics of the population

Representativeness Heuristic  

A rule of thumb where similarity to a prototype or similar situation dictates a decision.

Repression   

In Psychoanalytic Theory, the defense mechanism whereby our thoughts are pulled out of our consciousness and into our unconscious.

Resistance

In psychoanalysis, the client's refusal to participate in a therapeutic intervention due to underlying issues unrelated to the intervention.

Response Prevention

A therapeutic technique where stimuli is presented to the client but the client is not permitted to exercise his or her typical response.  Used for the treatment of phobias, obsessive compulsive disorder and other anxiety disorders.

Reticular Formation (Reticular Activating System)

Part of the brain stem involved in arousal and attention, sleep and wakefulness, and control of reflexes.

Retinal Disparity

The binocular cue to distance referring to the distance between the two images sent to the brain by our eyes.  The farther apart these images, the closer the object.

Retrieval   

The process of bringing material out of long term memory and into consciousness.

Retroactive Interference

Interference in memory created by later learning.

Reversal Design

Any single subject design that includes the removal of treatment to determine if the subject reverts to baseline (ex. ABA, ABAB)

Reversibility

A child's ability to reverse operations and therefore recognize that the qualities of an object remain the same despite changes in appearance.  Occurs in Piaget's Concrete Operational Stage of Cognitive Development (e.g., 1+2=3 to 3-2=1).

Reward Power  

Power derived through an ability to offer rewards.

Rogers, Carl   

A humanistic Psychologist who developed Client-Centered Therapy.

Rorschach Inkblot Test   

A projective technique utilizing ambiguous inkblots as stimuli.