| A | B |
|---|
| Experimenter bias | The paticipants in an experiment who receive the drug or other treatment under study - that is, those who are exposed to the charge that the independent variable represents. |
| Demand Characteristics | Any aspects of a study that communicate to the participants how the experimenter wants them to behave. |
| Research Participant Bias | In an experiment, the influence of participants' expectations, and their thoughts on how they should behave, on their behavior. |
| Placebo Effect | A phenomenon in which the participants' expectations,rather than an actual treatment, produce an outcome. |
| Placebo | In a drug study, a harmless substance that has no physiological effect, given to participants in a control group so that they are treated identically to the experimental group except for the active agent. |
| Double-Blind Experiment | An experimental design in which neither the experimenter nor the participants are aware of which participants are in the experimental group until the results are calculated. |
| Population | The entire group about which the investigator wants to draw conclusions. |
| Sample | The subset of the population chosen by the investigator for study. |
| Random Sample | A sample that gives every member of the population an equal chance of being selected. |
| Naturalistic Observation | The observation of behavior in a real-world setting. |
| Descriptive Statistics | Mathematical procedures that are used to desribe and summarize sets of data in a meaningful way. |
| Mean | A measure of central tendencythat is the average for a sample. |
| Median | A measure of central tendency that is the middle scorein a sample. |
| Mode | A measure of central tendency that is the most common score in a sample. |
| Range | A measure of dispersion that is the difference between the highest and lowest scores. |
| Variable | Anything that can change. |
| Theory | A broad idea or set closely related ideas that attempts to explain observations and to make predictions about future obseervations. |
| Hypothesis | An educated guess that derives logically from a theory; a prediction that can be tested. |
| Operational Definition | A definition that provides an objective description of how a variable is going to be measured and observed in a particular study. |
| Descriptive Research | Research that determinesthe basic dimensions of a phenomenon, defining what it is, how often it occurs, and so on. |
| Case Study or Case History | An in-depth look at a single individual. |
| Correlational Research | Research that examines the relations between variables with the purpose of determining whether and how two variables change together. |
| Third Variable Problem | The circumstance where a variable that has not been measured accounts for the relationship between two other variables. |
| Cross-Sectional Design | A type of correlation study in which variables are measured at a single point in time. |
| Longitudinal Design | A special kind of systematci observation, used by correlational researchers, that involves obtaining measures of the variable of interest in multiple waves overtime. |
| Experiment | A carefully regulated procedure in which the researcher manipulates one or more variables that are believed to influence some other variable. |
| Random Assignment | Researchers' assignment of participants to groups by chance, to reduce the likelihood that an experiment's results will be due to preexisting differences between groups. |
| Independent Variable | A manipulated experimental factor; the variable that the experimenter changes to see what its effects are. |
| Dependent Variable | The outcome; the factor that can change in an experiment in response to changes in the independent variable. |
| Confederate | A person who is given a role to play in a study so that the social context can be manipulated. |
| Experimental Group | The participants in an experiment who receive the drug or other treatment under study - that is, those who are exposed to the change that the independent variable represents. |
| Control Group | The participants in an experiment who are as much like the experimental group as possible and who are treated in every way like the experimental group except for a manipulated factor, the independent variable. |
| External Validity | The degree to which an experimental design actually reflects the real-world issues it is supposed to address. |
| Internal Validity | The degree to which changes in the dependent variable are due to manipulation of the independent variable. |
| Standard Deviation | A measure of dispersion that tells us how much scored in a sample differ from the mean of the sample. |
| Inferential Statistics | Mathematical methods that are used to indicate whether results for a sample are likely to generalize to a population. |
