AP Psych - Scientific Method

FLASHCARDS

Hypothesis

a testable prediction about the relationship between variables, based on existing theories and research

Theory

a well-supported, integrated set of principles that organizes observations and explains phenomena (events/behaviors), allowing psychologists to predict future outcomes

Overconfidence

the psychological bias where an individual overestimates their own abilities, knowledge, or control, leading to a distorted and overly optimistic view of their performance and potential success

Operational definition

explaining a concept by how you measure or observe it, turning an abstract idea (like "happiness") into a concrete, specific procedure

Replication

repeating a research study, often with different people or in different settings, to see if the original findings hold true, thereby verifying their reliability, validity, and generalizability across time and situations

Case study

an in-depth, detailed investigation of a single person, small group, event, or organization, using various methods (interviews, observation, records) to understand unique behaviors, experiences, or rare conditions, providing rich qualitative data to explore complex issues and test theories, though findings aren't always generalizable to the wider population

Naturalistic observation

watching and recording people's behaviors in their real-life, everyday environments without interfering

Survey

a quantitative research method collecting data from a sample of individuals using standardized questions (via questionnaires or interviews) to understand broader population attitudes, behaviors, opinions, and experiences

Social desirability bias

the tendency for people to answer questions in a way that makes them look good or socially acceptable, rather than truthfully, by overstating positive traits/behaviors (like exercising) and underreporting negative ones (like smoking) to fit in or avoid judgment

Self-report bias

the tendency for individuals to provide inaccurate or distorted information about themselves in a self-report measure, such as a survey or interview

Sampling bias

a systematic error that occurs when the selection of research participants is not random and does not accurately represent the population being studied, leading to skewed results and flawed conclusions

Random sample

a subset of individuals chosen from a larger population where every single person has an equal chance of being selected

Population

the entire group of individuals sharing common characteristics that a researcher wants to study and draw conclusions about

Correlation

a statistical measure showing the extent to which two or more variables change together, indicating a pattern or relationship

Correlation coefficient

(r) is a number between -1 and +1 that measures the strength and direction of the linear relationship between two variables, showing how much they change together; a positive r (e.g., +0.8) means they rise/fall together, a negative r (e.g., -0.8) means one goes up as the other goes down, and r = 0 means no linear link, with numbers closer to 1 or -1 indicating a stronger connection

Single-blind procedure

a research method where participants don't know if they're in the real treatment group or a control group (like getting a placebo), but the researchers do know, helping to prevent participant bias from expectations but leaving room for researcher bias

Double-blind procedure

an experiment where neither the participants nor the researchers know who is getting the real treatment and who is getting a placebo (fake treatment), preventing bias from expectations (placebo effect or researcher influence) and ensuring more objective results about the treatment's effectiveness. 

Placebo effect

a phenomenon where a person experiences a real improvement in their condition (like reduced pain or better mood) after receiving an inactive "fake" treatment (a placebo) simply because they expect it to work, demonstrating the mind's powerful influence over the body's healing processes and symptoms, often through belief, context, and ritual. 

Confounding variable

an "extra" or hidden factor that influences both the independent (manipulated) and dependent (measured) variables, muddying the results and making it seem like the independent variable caused an effect when it was actually the confounder, ruining the experiment's validity

Experimenter bias

the unconscious tendency of a researcher to influence study outcomes to align with their expectations or hypotheses, affecting data collection, interpretation, and reporting

Quantitative research

uses numbers, statistics, and large samples to measure, test, and find patterns in behaviors, thoughts, and emotions

Qualitative research

explores deep understanding of human experiences, behaviors, and meanings using non-numerical data (words, images) through methods like interviews, observations, and focus groups, focusing on the why and how behind actions rather than just how many, to uncover rich, contextual insights into complex phenomena

Informed consent

a person's voluntary agreement to join a study or treatment after fully understanding its purpose, procedures, potential risks, and benefits, ensuring they can freely choose to participate or withdraw without penalty, based on clear, understandable information

Debriefing

a post-research meeting where researchers fully explain the study's true purpose, methods, and any deception used, ensuring participants understand the experience, can ask questions, and leave in the same psychological state as before, protecting their well-being and upholding ethical standards

Mode

most frequent value

Mean

average value

Median

middle value (least to greatest)

Standard deviation

a simple measure of data spread, showing the average distance scores in a group fall from the mean (average); a small SD means scores cluster near the average (consistent), while a large SD means scores are spread out (diverse)

Normal curve

a symmetrical, bell-shaped graph that represents data where most scores cluster around the average (mean), with fewer scores at the extremes

Meta-analysis

a powerful statistical method that combines results from multiple independent studies on the same topic to find an overall, more precise conclusion, revealing hidden patterns and providing stronger evidence than single studies, often by calculating a combined "effect size" to see the big picture and understand variations

Statistical significance

a research finding (like a difference between groups or a relationship between variables) is unlikely to be due to random chance, suggesting it's a real effect, often indicated by a p-value below 0.05 (meaning less than 5% chance of being random)