Term	Definition/Explanation
case study	In-depth examination of an individual or small group over an extended period, often using a variety of data sources such as interviews, observations, and psychological tests.
confounding variable	A variable other than the independent variable that could potentially influence the dependent variable, leading to inaccurate interpretations of the results.
control group	The group in an experiment that does not receive the treatment or intervention, used for comparison with the experimental group.
correlation	A statistical measure of the relationship between two variables, indicating how they change together. However, correlation does not imply causation.
correlation coefficient	A numerical value between -1 and +1 that represents the strength and direction of the relationship between two variables.
critical thinking	The objective analysis and evaluation of an issue to form a judgment. It involves questioning assumptions, examining evidence, and considering alternative perspectives.
debriefing	The process of providing participants with information about the purpose, procedures, and results of a research study after their participation, especially if deception was used.
dependent variable	The variable that is measured or observed in an experiment and is expected to change as a result of the manipulation of the independent variable.
descriptive statistics	Statistical techniques used to summarize and describe the characteristics or properties of a dataset, such as measures of central tendency and variability.
double-blind procedure	An experimental procedure in which both the participants and the researchers involved are unaware of who is assigned to the experimental or control group, reducing bias.
effect size	A measure of the strength or magnitude of the relationship between variables or the magnitude of a treatment effect, independent of sample size.
experiment	A research method in which one or more variables are manipulated to observe the effect on another variable, while controlling for extraneous factors.
experimental group	The group in an experiment that is exposed to the treatment or intervention being studied.
experimenter bias	The influence of the researcher's expectations or beliefs on the outcomes of an experiment, leading to unintentional bias in data collection or interpretation.
falsifiability	The principle that for a hypothesis or theory to be considered scientific, it must be possible to conceive of evidence that would prove it false.
hindsight bias	The tendency to believe, after learning an outcome, that one would have foreseen it. It's often referred to as the "I knew it all along" phenomenon.
histogram	A graphical representation of the distribution of numerical data, where the data is divided into intervals (bins) and the height of each bar represents the frequency or count of data points within each interval.
hypotheses	Testable predictions or educated guesses about the relationship between two or more variables, typically formulated as statements.
illusory correlation	The perception of a relationship between two variables when no such relationship exists, or the perceived relationship is weaker than it appears.
independent variable	The variable that is manipulated or controlled by the researcher in an experiment to observe its effect on the dependent variable.
inferential statistics	Statistical techniques used to make inferences or predictions about a population based on sample data, including hypothesis testing and estimation.
informed consent	The ethical principle requiring that participants in a research study are fully informed about the nature, purpose, risks, and benefits of participation before agreeing to take part.
mean	The average of a set of values, calculated by summing all values and dividing by the number of values.
median	The middle value in a dataset when the values are arranged in ascending or descending order. If there is an even number of values, the median is the average of the two middle values.
meta-analysis	A statistical technique for combining the findings from multiple studies on a particular topic to determine overall trends or effects.
mode	The most frequently occurring value in a dataset.
naturalistic observation	Observation of behavior in its natural context without interference or manipulation by the researcher.
normal curve	A symmetrical, bell-shaped curve that represents the distribution of scores in a population, with the mean, median, and mode all located at the center.
operational definitions	Precise descriptions of how variables in a study will be manipulated or measured. They specify the procedures used to define and measure concepts.
peer reviews	The evaluation of scientific, academic, or professional work by others in the same field to ensure its quality and validity before publication or presentation.
percentile rank	The percentage of scores in a distribution that are equal to or below a particular score.
placebo	An inactive substance or treatment that resembles the experimental treatment, used in research to control for the psychological effects of receiving treatment.
placebo effect	The phenomenon where individuals experience a change in their condition or behavior after receiving a placebo, due to their belief in the effectiveness of the treatment.
population	The entire group of individuals or cases that researchers are interested in studying and to which they intend to generalize their findings.
qualitative research	Research that focuses on gathering and analyzing non-numerical data, such as observations, interviews, or textual analysis, to understand meanings, experiences, or perspectives.
quantitative research	Research that focuses on gathering and analyzing numerical data to understand relationships, patterns, or trends.
random assignment	The process of assigning participants to experimental or control groups in a way that each individual has an equal chance of being placed in any group, reducing the likelihood of bias.
random sample	A sample in which every member of the population has an equal chance of being selected to participate in the study, increasing the generalizability of the findings.
range	The difference between the highest and lowest values in a dataset, representing the spread or dispersion of the data.
regression toward the mean	The tendency for extreme or unusual scores on a variable to move closer to the average or mean when measured again.
replicate	To repeat a research study or experiment to determine if the findings can be reliably reproduced.
sampling bias	A bias in which a sample is not representative of the population from which it is drawn, leading to inaccurate or ungeneralizable results.
scatterplot	A graphical representation of the relationship between two variables, where each data point represents an individual's score on both variables.
self-report bias	Inaccuracies or distortions in responses to surveys or questionnaires due to factors such as social desirability, memory recall, or misunderstanding of questions.
single-blind procedure	An experimental procedure in which either the participants or the researchers involved are unaware of who is assigned to the experimental or control group.
skewed distribution	A distribution of data in which the scores cluster more towards one end (positive skew) or the other end (negative skew) of the range, rather than being evenly distributed.
social desirability bias	The tendency for people to respond in a manner that they believe is socially acceptable or desirable, rather than providing honest or accurate answers.
standard deviation	A measure of the average distance of each data point from the mean of the dataset, indicating the degree of variability or dispersion in the data.
statistical significance	The likelihood that the results of a study are not due to chance, typically determined by comparing observed data with expected outcomes under the null hypothesis.
survey	A research method that involves collecting data from a population through the use of questionnaires or interviews to gather information about attitudes, beliefs, behaviors, or characteristics.
theory	A well-supported explanation for a phenomenon based on evidence, observation, and experimentation. It integrates and organizes a set of related principles or concepts.
validity	The extent to which a research study measures what it claims to measure or accurately reflects the concept or phenomenon being studied.
variable	Any factor or condition that can change or vary in a research study. Variables are typically categorized as independent or dependent.

absolute threshold	The minimum stimulation needed to detect a particular stimulus 50% of the time.
accomodation	In vision, the process by which the lens of the eye shifts to focus on a particular object.
acetylcholine	A neurotransmitter involved in muscle activation, memory, and learning.
action potential	A brief electrical charge that travels down the axon of a neuron, generated by the movement of positively charged atoms in and out of channels in the neuron's membrane.
Activation-Synthesis Theory	A theory of dreaming that suggests dreams are the brain's attempt to make sense of random neural activity.
addiction	A complex condition characterized by compulsive drug use or behaviors despite harmful consequences.
agonist	A drug or chemical that enhances the activity of neurotransmitters.
Alcohol	A depressant that slows down the central nervous system, impairing cognitive and motor functions.
all-or-none response	The principle that a neuron either fires completely or does not fire at all.
alpha waves	The relatively slow brain waves associated with relaxation and wakefulness.
Amplitude	The height of a wave, which determines the loudness of a sound.
amygdala	A limbic system structure involved in processing emotions, particularly fear and aggression.
antagonist	A drug or chemical that inhibits or blocks the action of neurotransmitters.
Aphasia	A condition characterized by the loss of ability to understand or express speech.
association areas	Areas of the cerebral cortex that are not involved in primary motor or sensory functions but are involved in higher mental functions such as learning, remembering, thinking, and speaking.
audition	The sense of hearing.
Auditory Cortex	The part of the brain that processes auditory information.
autonomic nervous system	The part of the peripheral nervous system that controls involuntary functions like heart rate, digestion, and glandular secretion.
axon	The extension of a neuron through which neural impulses are sent.
barbiturates	A class of drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment.
behavior genetics	The study of the relative power and limits of genetic and environmental influences on behavior.
biological psychology	A branch of psychology concerned with the links between biology and behavior.
biopsychosocial approach	An integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.
blind spot	The point at which the optic nerve leaves the eye, creating a small gap in the field of vision.
blindsight	A condition in which a person can respond to visual stimuli without consciously experiencing them.
bottom-up processing	Analysis that begins with sensory receptors and works up to the brain's integration of sensory information.
brainstem	The oldest part and central core of the brain, responsible for automatic survival functions.
Broca's Area	A region in the frontal lobe of the brain associated with speech production.
Caffeine	A stimulant found in coffee, tea, and many soft drinks that increases alertness and reduces fatigue.
central nervous system	The brain and spinal cord, responsible for processing and coordinating information.
cerebellum	A structure in the hindbrain that helps coordinate voluntary movement and balance.
cerebral cortex	The outer layer of the brain responsible for complex cognitive processes such as thinking, planning, and language.
Charles Darwin	An English naturalist who proposed the theory of evolution by natural selection.
circadian rhythm	The biological clock; regular bodily rhythms that occur on a 24-hour cycle.
Cocaine	A powerful stimulant drug that increases levels of dopamine in the brain, leading to intense euphoria and increased energy.
cochlea	A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
cochlear implant	A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
cognitive neuroscience	The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language).
computed tomography (CT)	A scanning technique using multiple X-rays to construct a 3D image of the brain's structure.
conduction hearing loss	Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

accomodation	In Piaget's theory of cognitive development, the process of modifying existing cognitive structures in response to new information or experiences.
achievement test	A test designed to assess what a person has learned or accomplished in a particular area, such as academic subjects or job-related skills.
Alfred Binet	A French psychologist known for developing the first intelligence test, which aimed to measure children's mental abilities and predict their academic success.
algorithm	A step-by-step procedure or formula for solving a problem, often involving repetitive operations.
Alzheimer's Disease	A progressive neurodegenerative disorder characterized by memory loss, language deterioration, and impaired ability to mentally manipulate visual information.
Amnesia	A significant memory loss that is too extensive to be due to normal forgetting.
Amos Tversky	A cognitive psychologist known for his collaboration with Daniel Kahneman on decision-making and heuristics.
anterograde amnesia	A type of memory impairment characterized by the inability to form new memories after a specific event or injury, while memories from before the event remain intact.
aptitude test	A test designed to assess a person's potential for learning or ability to perform in a particular area, such as intelligence tests or vocational aptitude tests.
assimilation	In Piaget's theory of cognitive development, the process of incorporating new information or experiences into existing cognitive structures or schemas.
Attention	The cognitive process of selectively focusing on a specific aspect of information while ignoring other perceivable information.
Autobiographical Memory	A person's memory for events and issues related to oneself.
autokinetic effect	A perceptual phenomenon where a stationary point of light appears to move in a dark environment due to small eye movements.
automatic processing	The unconscious processing of information that requires minimal attention and effort, such as routine tasks or well-learned skills.
availability heuristic	A mental shortcut where people make judgments based on the ease with which examples come to mind, often leading to overestimating the likelihood of events based on their availability in memory.
belief perserverance	The tendency to maintain one's beliefs even in the face of contradictory evidence.
binocular cue	Depth cues that rely on information from both eyes to perceive depth and distance, such as retinal disparity and convergence.
Bottom-Up Processing	An approach to perception that starts with incoming stimuli and builds up to a final perception; involves analysis that begins with the sensory receptors and works up to the brain's integration of sensory information.
Carol Dweck	A psychologist known for her research on motivation and mindset, particularly the concepts of fixed mindset and growth mindset.
Cattell-Horn-Carroll theory	A contemporary theory of intelligence proposing that intelligence is composed of multiple distinct abilities, including fluid intelligence, crystallized intelligence, and various specific cognitive skills.
central executive	In Baddeley's model of working memory, the component responsible for coordinating and controlling cognitive processes, including attention, planning, and decision-making.
Change Blindness	A phenomenon in visual perception where changes in a visual stimulus are not noticed by the observer.
Charles Spearman	A British psychologist known for his work on intelligence and the development of factor analysis, which identified a general factor of intelligence (g factor) underlying performance on cognitive tasks.
chunking	Organizing information into smaller, more manageable units or chunks to improve memory and processing efficiency.
Cocktail Party Effect	The phenomenon of being able to focus one's auditory attention on a particular stimulus while filtering out a range of other stimuli, like hearing your name in a noisy room.
cognition	The mental processes involved in acquiring, processing, storing, and retrieving information, including perception, thinking, memory, and problem-solving.
cohort	A group of individuals who share a common characteristic or experience, such as age or generation, and are studied over time in longitudinal research.
color constancy	The perceptual phenomenon where the perceived color of an object remains relatively constant under different lighting conditions.
concept	A mental category or representation of objects, events, or ideas that share common features or characteristics.
confirmation bias	The tendency to search for, interpret, and remember information that confirms one's preexisting beliefs or hypotheses while ignoring or discounting contradictory evidence.
construct validity	The extent to which a test or measure accurately assesses the theoretical construct or concept it is intended to measure.
Constructive Memory	The process of constructing a memory by integrating new information with existing knowledge.
content validity	The extent to which a test or measure adequately samples the domain of interest and includes all relevant aspects of the construct being assessed.
Context-Dependent Memory	The improved recall of information when the context present at encoding and retrieval are the same.
convergence	A binocular depth cue where the eyes turn inward or converge to focus on nearby objects.
convergent thinking	A type of thinking characterized by narrowing down possible solutions to find a single correct answer, often associated with traditional problem-solving tasks.
creativity	The ability to generate novel and valuable ideas, solutions, or products that are meaningful or useful in a particular context.
cross-sectional study	A research design that compares different groups of individuals at a single point in time to examine age-related differences.
crystallized intelligence	Acquired knowledge and skills accumulated over a lifetime, often measured by vocabulary tests and general knowledge assessments.
Daniel Kahnman	A psychologist known for his work on decision-making, heuristics, and biases, particularly in collaboration with Amos Tversky.

AP Psych Vocab