- archival research
- method of research using past records or data sets to answer various research questions, or to search for interesting patterns or relationships
- attrition
- reduction in number of research participants as some drop out of the study over time
- cause-and-effect relationship
- changes in one variable cause the changes in the other variable; can be determined only through an experimental research design
- clinical or case study
- observational research study focusing on one or a few people
- confirmation bias
- tendency to ignore evidence that disproves ideas or beliefs
- confounding variable
- unanticipated outside factor that affects both variables of interest, often giving the false impression that changes in one variable causes changes in the other variable, when, in actuality, the outside factor causes changes in both variables
- control group
- serves as a basis for comparison and controls for chance factors that might influence the results of the study—by holding such factors constant across groups so that the experimental manipulation is the only difference between groups
- correlation
- relationship between two or more variables; when two variables are correlated, one variable changes as the other does
- correlation coefficient
- number from -1 to +1, indicating the strength and direction of the relationship between variables, and usually represented by r
- cross-sectional research
- compares multiple segments of a population at a single time
- debriefing
- when an experiment involved deception, participants are told complete and truthful information about the experiment at its conclusion
- deception
- purposely misleading experiment participants in order to maintain the integrity of the experiment
- deductive reasoning
- results are predicted based on a general premise
- dependent variable
- variable that the researcher measures to see how much effect the independent variable had
- double-blind study
- experiment in which both the researchers and the participants are blind to group assignments
- empirical
- grounded in objective, tangible evidence that can be observed time and time again, regardless of who is observing
- experimental group
- group designed to answer the research question; experimental manipulation is the only difference between the experimental and control groups, so any differences between the two are due to experimental manipulation rather than chance
- experimenter bias
- researcher expectations skew the results of the study
- fact
- objective and verifiable observation, established using evidence collected through empirical research
- falsifiable
- able to be disproven by experimental results
- generalize
- inferring that the results for a sample apply to the larger population
- hypothesis
- (plural: hypotheses) a testable prediction about how the world will behave if an idea is correct, often worded as an if-then statement
- illusory correlation
- seeing relationships between two things when in reality no such relationship exists
- independent variable
- variable that is influenced or controlled by the experimenter; in a sound experimental study, the independent variable is the only important difference between the experimental and control group
- inductive reasoning
- conclusions are drawn from observations
- informed consent
- process of informing a research participant about what to expect during an experiment, any risks involved, and the implications of the research, and then obtaining the person’s consent to participate
- Institutional Animal Care and Use Committee (IACUC)
- committee of administrators, scientists, veterinarians, and community members that reviews proposals for research involving non-human animals
- Institutional Review Board (IRB)
- committee of administrators, scientists, and community members that reviews proposals for research involving human participants
- inter-rater reliability
- measure of agreement among observers on how they record and classify a particular event
- longitudinal research
- studies in which the same group of individuals is surveyed or measured repeatedly over an extended period of time
- naturalistic observation
- observation of behavior in its natural setting
- negative correlation
- two variables change in different directions, with one becoming larger as the other becomes smaller; a negative correlation is not the same thing as no correlation
- observer bias
- when observations may be skewed to align with observer expectations
- operational definition
- description of what actions and operations will be used to measure the dependent variables and manipulate the independent variables
- opinion
- personal judgments, conclusions, or attitudes that may or may not be accurate
- participants
- subjects of psychological research
- peer-reviewed journal article
- article read by several other scientists (usually anonymously) with expertise in the subject matter, who provide feedback regarding the quality of the manuscript before it is accepted for publication
- placebo effect
- people's expectations or beliefs influencing or determining their experience in a given situation
- population
- overall group of individuals that the researchers are interested in
- positive correlation
- two variables change in the same direction, both becoming either larger or smaller
- random assignment
- method of experimental group assignment in which all participants have an equal chance of being assigned to either group
- random sample
- subset of a larger population in which every member of the population has an equal chance of being selected
- reliability
- consistency and reproducibility of a given result
- replicate
- repeating an experiment using different samples to determine the research’s reliability
- sample
- subset of individuals selected from the larger population
- single-blind study
- experiment in which the researcher knows which participants are in the experimental group and which are in the control group
- statistical analysis
- determines how likely any difference between experimental groups is due to chance
- survey
- list of questions to be answered by research participants—given as paper-and-pencil questionnaires, administered electronically, or conducted verbally—allowing researchers to collect data from a large number of people
- theory
- well-developed set of ideas that propose an explanation for observed phenomena
- validity
- accuracy of a given result in measuring what it is designed to measure