Unit 0 Vocab

Experimental vs. non-experimental

Experimental methods of investigation involve manipulation of variables, whereas, non-experimental methods don't include any manipulation of variables (case studies, naturalistic observation, meta-analysis, correlation)

Independent variable (IV)

The experimental factor that is manipulated; the variable whose effect is being studied.

Dependent variable (DV)

The outcome factor; the variable that may change in response to manipulations of the independent variable.

Confounding variables

A factor other than the independent variable that might produce an effect in an experiment.

Random assignment

Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups.

Population

All those in a group being studied, from which samples may be drawn. (Note: Except for national studies, this does not refer to a country's whole population.)

Sample

Who the researcher is studying pulled out of the population. (ideally it is random)

Random sampling

A sample that fairly represents a population because each member has an equal chance of inclusion.

Representative samples

An equally representative sample that accurately represents the demographics and characteristics of the population.

Convenience samples

The process of selecting participants who are readily available, but may not provide a representative sample.

Sampling bias

Bias that involves intentionally collecting a sample is not representative of the population.

Generalizability

The ability to apply information found in a study to the general population, often associated with metrics like statistical significance.

Experimental group

The group in an experiment that receives the treatment or manipulation.

Control group

The group in an experiment that does not receive any actual treatment; allows researchers to compare results and draw conclusions about the effects of the treatment.

Placebo group

A group in an experiment that is given a false treatment with no real effect.

Placebo effect

The phenomenon where participants experience changes simply because they believe they are receiving treatment.

Single-blind procedure

Research design in which participants don't know whether they are in the experimental or control group.

Double-blind procedure

An experimental procedure in which neither the participants nor researchers know if participants have received treatment or a placebo.

Experimenter bias

Bias that occurs when researchers' expectations influence the outcome of an experiment.

Case study

The in-depth study of one person or one group.

Correlation (does not equal causation)

The examination of the relationship between two or more variables (cannot establish cause and effect relationships).

Positive correlation

A relationship between two variables where as one variable increases, the other also increases.

Negative correlation

A relationship between two variables where as one variable decreases, the other also decreases.

Directionality problem

This problem refers to confusion in determining which of the two variables are influencing which variables in correlational relationships.

Third-variable problem

When a third, unmeasured variable influences both variables studied in a correlational relationship and potentially leads to misleading conclusions about their relationship.

Scatterplots

A graphical representation of the relationship between two variables, with each point on the scatterplot representing an observation.

Correlation coefficient

The numerical value that represents the strength and direction of a correlation. (the value ranges from -1 to +1)

Quantitative measures (e.g. Likert scales)

Tools used to measure numerical data (Likert scales, Surveys, Psychological tests).

Qualitative measures

Tools used to measure observational data (Focus Groups, Observations, Case Studies, (Un)structured Interviews).

Surveys

A research method that employs questionnaires or interviews to collect data from a large group of people.

Framing

The way an issue is presented or 'framed', which can significantly affect decisions and judgments.

Social desirability bias

Bias in a study when respondents give socially acceptable rather than truthful answers. Ex. A high school student lying about smoking.

Self-report bias

Bias in a study when participants provide inaccurate information about themselves.

Meta-analysis

A research method that statistically combines the results of studies to reach a conclusion.

Naturalistic observation

A research method in which behavior is observed in its natural setting without intervention.

Hypothesis

A specific, testable prediction derived from a theory.

Falsifiability

The ability to disprove something using factual evidence.

Operational definitions

A specified definition of how a concept is measured or manipulated in a study.

Replication and Peer review

Replication is the ability to repeat a study and achieve the same results, while peer review refers to the evaluation of quality/variety of research by peers to ensure that research methods are reliable and the conclusions are valid.

Ethical guidelines

Certain rules established by professional organizations and institutional review boards to protect the rights and well-being of participants.

Institutional review board

A committee that reviews and approves research proposals to assure that they meet ethical and humane standards.

Informed consent

In an ethical study, participants must be fully informed about the research and its potential risks and benefits before agreeing to participate.

Informed assent

Consent for minors or individuals with diminished capacity (impairments), assent is obtained alongside the consent from a legal guardian.

Protection from harm

Researchers must abide by safety standards and take precautions to minimize any physical or psychological harm to participants. This also includes providing participants with the right to withdrawal at any time without penalty.

Confidentiality of participants

Participant information is kept private and secure in a study.

Minimal deception

The employment of deception to create a realistic situation in certain experimental settings; it is often used to produce certain characteristics or behaviors.

Confederates

Individuals who act as participants, but are a part of the research team, sometimes used in deception studies.

Debriefing

Participants must be fully informed about the research, including the use of deception, and are allowed to ask questions about the research.

Central tendency

Measures to calculate where the 'center' of the data lies (mean, median, mode).

Measures of variation

Measures used to calculate the spread or dispersion of data. Range refers to the spread of the data values, while the standard deviation describes the average distance of each score from the mean.

Normal curve

A statistical curve on a graph ('bell curve') where the mean, median, and mode are all equal and located at the center of the curve.

Positive and negative skews

A positive skew refers to data skewed towards the right side of the graph, while a negative skew demonstrates data being clustered toward the left side of the graph.

Bimodal distributions

A distribution with two distinct peaks of clustered data.

Regression toward the mean

The tendency for extreme or unusual scores to fall back (regress) toward the average of the data.

Statistical significance

The probability that the results of a study are not simply by chance, but are supported by evidence.

Effect sizes

A measure of the magnitude or strength of the relationship between variables or the difference between groups.

Cognitive biases

Bias that can affect the data or interpretation of data collected in a study (confirmation bias, hindsight bias, overconfidence).