Glossary Items Starting with "O"

objective measure: Any measure that requires little or no judgment on the part of the person making the measurement. Objective measures are more resistant to experimenter biases than subjective measures.
observation: Empirical process in which data about the phenomenon are gathered and reported. Observation is the central task in all research.
observation phase of research: Research phase in which the data are gathered.
observational variable: Any variable that is observed and not manipulated in research. The term is usually used in low-constraint research, in which the independent and dependent variable distinction does not apply.
observed organismic variable: Any characteristic of the participant that can be measured and used for classification.
one-way ANOVA: Statistical procedure that evaluates differences in mean scores of two or more groups in which the groups are defined by a single independent variable.
open-ended items: Items or questions on a questionnaire that the respondent answers in his or her own words.
operational definition: Detailed set of procedures used to measure or manipulate the level of a variable.
ordered data: Data produced by ordinal scales of measurement.
orderliness belief: Belief dating from ancient artisans that events in nature are predictable.
ordinal scale: Scale of measurement in which the scores can be rank ordered but the distance between any two adjacent scores will not necessarily be the same as the distance between any other two adjacent scores.
ordinate: The y-axis on a graph.
organismic variable: Any characteristic of the participant that can be used for classification. An organismic variable may be either directly observed (observed organismic variable) or may be inferred on the basis of the responses of the participant (response-inferred organismic variable).
outline: The essential features or main aspects of ideas, organized under headings and subheadings.