Unit 0 Vocab

Experimental vs. non-experimental- Experimental designs allow observation of a phenomenon as it naturally occurs, and nonexperimental designs permit environmental manipulation.


Independent variable (IV)- the variable that is manipulated in an experiment to assess if it will effect dependent variable


Meta-analysis- combines the results of multiple scientific studies


Naturalistic observation- a method that involves observing subjects in their natural environment


Dependent variable (DV)- the variable that changes as a result of the independent variable manipulation


Confounding variables- a third variable in a study examining a potential cause-and-effect relationship


Random assignment- every participant having an equal chance of being in either the experimental group or the control group


Population-All the cases in a group being studied, from which samples may be drawn


Sample- a small subset of individuals intended to reflect specified characteristics present in a target population.


Random sampling- when the group of subjects in your experiment accurately depicts the population


Representative samples- a smaller subset of a larger groups that accurately reflects specific characteristics of that population.


Convenience samples- asking anyone who happens to be there if they would like to participate


Sampling bias- occurs when some members of a population are systematically more likely to be selected in a sample than others


Generalizability- Responses to a new stimulus based on prior experience with similar stimuli.


Experimental group- the group in an experiment that receives the variable being tested


Control group- the group that does not receive the independent variable in an experiment


Placebo group-  group that receives what, to them, appears to be a treatment, but actually is neutral and does not contain any active treatment


Placebo effect- when a group of people feel an effect of a drug when they have actually only ingested a placebo


Single-blind procedure- when the subjects do not know all of the information about the study while it is occurring, especially which group (experiment


Double-blind procedure- when neither the participant in the study nor the person giving the study know who is the control group and who is in the experimental group


Experimenter bias- hen the experimenter affects the results of their own study because of their expectations


Case study- a thorough study of a single person, community or event that relies on observations, facts and experiments to gather information.


Correlation (does not equal causation)- indicates the possibility of a cause-effect relationship, but it does not prove causation or, if causation exists, the direction of the influence.


Positive correlation- when the two variables move in the same direction


Negative correlation- the relationship between two variables in which one variable increases as the other variable decreases.


Directionality problem-  significant correlation does not provide information about the direction of the relationship.


Third-variable problem- A type of confounding in which a third variable leads to a mistaken causal relationship between two others


Scatterplots: Graphs showing the relationship between two variables using data points.

Correlation Coefficient: A number that shows how strongly two variables are related.

Quantitative Measures: Data that can be counted or measured (e.g., numbers on a scale).

Qualitative Measures: Descriptive data, often from interviews or observations.

Surveys: A method of gathering information by asking questions to participants.


Framing- the way that a problem is presented to someone, and it can drastically change that person's view or reaction to the problem.


Social desirability bias-a type of response bias


Self-report bias- ny test, measure, or survey that relies on an individual's own report of their symptoms, behaviors, beliefs, or attitudes


Hypothesis- A tentative and testable explanation of the relationship between two (or more) events or variables


Falsifiability- the ability for a statement/theory to be shown to be false,


Operational definitions- sed to describe the procedure of a study and the research variables ( so it can be replicated)


Replication and Peer review 


Ethical guidelines- Informed consent, confidentiality, anonymity, and debriefing 


Institutional review board (for human and non- 

human research)- federally-mandated, locally-administered groups charged with evaluating risks and benefits of human participant research at their institution.


Informed consent- the subject is given enough information on the study to make an informed decision on his/her participation


Informed assent- an agreement by an individual not competent to give legally-valid informed consent


Protection from harm- researchers have a duty to protect participants from physical or psychological harm


Confidentiality of participants- the experimenters will not release any information about subjects without their consent 


Minimal deception- If the participants are deceived in any way about the nature of the study, the deception must not be so extreme as to invalidate the informed consent.


Confederates- an aide of the experimenter who poses as a participant but whose behavior is rehearsed prior to the experiment


Debriefing- when an experimenter tells the subject more information about the study's purpose and procedures after the study is completed


Central Tendency (Mean, Median, Mode):

  • Mean: The average of all data points.

  • Median: The middle value when data is ordered.

  • Mode: The value that occurs most often.

Measures of Variation (Range and Standard Deviation):

  • Range: The difference between the highest and lowest values.

  • Standard Deviation: A measure of how spread out the data is from the mean.

Normal Curve (Percentages and Percentiles):

  • A symmetrical bell-shaped curve where most data points are near the average.

  • Percentiles: The position of a value within a data set compared to others.

Positive and Negative Skews:

  • Positive Skew: When data is stretched to the right, with most values on the left.

  • Negative Skew: When data is stretched to the left, with most values on the right.

Bimodal Distributions: A data set with two distinct peaks or modes.

Regression toward the mean- following an extreme random event, the next random event is likely to be less extreme


Statistical significance-  it's unlikely to be explained solely by chance or random factors


Effect sizes- strength or magnitude of a relationship or difference between two variables in a study.



Cognitive biases (confirmation bias, hindsight bias, overconfidence)