A five-step process for empirical investigation of a hypothesis under conditions designed to control biases and subjective judgments.
An approach to research that relies on sensory experience and observation as research data.
A testable explanation for a set of facts or observations.
A statement predicting the outcome of a scientific study; a statement describing the relationship among variables in a study.
Specific descriptions of concepts involving the conditions of a scientific study.
A stimulus condition so named because the experimenter changes it independently of all the other carefully controlled experimental conditions.
A process by which chance alone determines the order in which the stimulus is presented.
Pieces of information, especially information gathered by a researcher to be used in testing a hypothesis.
The measured outcome of a study; the responses of the subjects in a study.
In research this refers to doing a study over to see whether the same results are obtained. As a control for bias, replication is often done by someone other than the researcher who performed the original study.
A kind of research in which the researcher controls all the conditions and directly manipulates the conditions, including the independent variable.
Variables that have an unwanted influence on the outcome of an experiment.
Constraints that the experimenter places on the experiment to ensure that each subject has the exact same conditions.
Each subject of the sample has an equal likelihood of being chosen for the experimental group of an experiment.
Ex Post Facto
Research in which we choose subjects based on a pre-existing condition.
A type of research that is mainly statistical in nature.
A quasi-experimental method in which questions are asked to subjects.
A research method in which subjects are observed in their natural environment.
A type of study in which one group of subjects is followed and observed.
A study in which a representative cross section of the population is tested or surveyed at one specific time.
A research method in which a cross section of the population is chosen and then each cohort is followed for a short period of time.
The researcher allowing personal beliefs to affect the outcome of a study.
The researcher allowing his or her expectations to affect the outcome of a study.
An experimental procedure in which both researchers and participants are uninformed about the nature of the independent variable being administered.
Institutional Review Board
A committee at each institution where research is conducted to review every experiment for ethics and methodology.
Institutional Animal Care and Use Committee
A committee at each institution where research is conducted to review every experiment involving animals for ethics and methodology.
ABCs of Laboratory Animal Research
Guiding principles in which research on animals is conducted. Governs the morality and ethical aspect of research on animals.
A summary chart, showing how frequently each of the scores in a set of data occurs.
A bar graph depicting a frequency distribution. The height of the bars indicates the frequency of a group of scores.
Statistical procedures used to describe characteristics and responses of groups of subjects.
The measure of central tendency most often used to describe a set of data--calculated by adding all the scores and diving by the number of scores. (mathematical average)
The measure of central tendency for a distribution, represented by the score the separates the upper half of the scores in a distribution from the lower half.
A measure of central tendency for a distribution, represented by the score that separates the upper half scores in a distribution from the lower half.
The simplest measure of variability, represented by the difference between the highest and the lowest values in a frequency distribution.
A measure of variability that indicates the average difference between the scores and their mean.
A relationship between variables, in which changes in one variable are reflected in changes in the other variable.
A bell-shaped curve, describing the spread of a characteristic throughout a population.
A number between -1 and +1 expressing the degree of relationship between two variables.
Statistical techniques used to assess whether the results of a study are reliable or whether they might be simply the result of a chance.
A sample group of subjects selected by chance.
A sample obtained in such a way that it reflects the distribution of important variables in the larger population in which the researchers are interested.
Psychologists accept a difference between the groups as "real", or significant, when the probability that it might be due to an atypical sample drawn by chance is less than 5 in 100.