AP PSYCH. CHP. 2- RESEARCH METHODS

208137059	Scientific Method	A 5-Step Process for empirical investigation of a hypothesis under conditions designed to control biases and subjective judgements.
208137060	Empirical Investigation	An approach to research that relies on sensory experience and observation as research data.
208137061	Theory	A testable explanation for a set of facts or observations. In science, this is not just a speculation or a guess.
208137062	Hypothesis	A statement predicting the outcome of a scientific study; a statement describing the relationship among variables in a study.
208137063	Operational Definitions	Specific descriptions of concepts involving the conditions of a scientific study. These are stated in terms of how the concepts are to be measured or what operations are being employed to produce them.
208137064	Independent Variable (IV)	A stimulus condition so named because the experimenter changes it independently of all the other carefully controlled experimental conditions.
208137065	Random Presentation	A process by which chance alone determines the order in which the stimulus is presented.
208137066	Data	Pieces of information, especially information gathered by a researcher to be used in testing a hypothesis.
208137067	Dependent Variable (DV)	The measured outcome of a study, the responses of the subjects in a study.
208137068	Replicate	In research, this refers to doing a study over to see whether the same results are obtained. As a control for bias, this is often done by someone other than the researcher who performed the original study.
208137069	Experiment	A kind of research in which the researcher controls all the conditions and directly manipulates the conditions, including the independent variable.
208137070	Confounding/Extraneous Variables	Variables that have an unwanted influence on the outcome of an experiment.
208137071	Controls	Constraints that the experimenter places on the experiment to ensure that each subject has the exact same conditions.
208137072	Random Assignment	Each subject of the sample has an equal likelihood of being chosen for the experimental group of an experiment.
208137073	Ex post factor	Research in which we choose subjects based on a pre-existing condition.
208137074	Correlational Study	A type of research that is mainly statistical in nature. These determine the relationship (or correlation) between two variables.
208137075	Survey	A quasi-experimental method in which questions are asked to subjects. When designing one, the researcher has to be careful that the questions are not skewed or biased toward a particular answer.
208137076	Naturalistic Observation	A research method in which subjects are observed in their natural environment.
208137077	Longitudinal Study	A type of study in which one group of subjects is followed and observed (or examined, surveyed, etc.) for an extended period of time (years).
208137078	Cross-Sectional Study	A study in which a representative cross section of the population is tested or surveyed at one specific time.
208137079	Cohort-sequential Study	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.
208137080	Personal Bias	The researcher allowing personal beliefs to affect the outcome of a study.
208137081	Expectancy Bias	The researcher allowing his or her expectations to affect the outcome of a study.
208137082	Double-Blind Study	An experimental procedure in which both researchers and participants are uninformed about the nature of the independent variable being administered.
208137083	Institutional Review Board (IRB)	A committee at each institution where research is conducted to review every experiment for ethics and methodology.
208137084	Institutional Animal Care and Use Committee (IACUC)	A committee at each institution where research is conducted to review every experiment involving animals for ethic and methodology.
208137085	Frequency Distribution	A summary chart, showing how frequently each of the various scores in a set of data occurs.
208137086	Histogram	A bar graph depicting a frequency of distribution. The height of the bars indicates the frequency of a group of scores.
208137087	Descriptive Statistics	Statistical procedures used to describe characteristics and responses of groups of subjects.
208137088	Mean	The measure of central tendency most often used to describe a set of data- calculated by adding all the scores and dividing by the number of scores.
208137089	Median	A measure of central tendency for a distribution, represented by the score that separates the upper half of the scores in a distribution from the lower half
208137090	Mode	A measure of central tendency for a distribution, represented by the score that occurs more often than any other.
208137091	Range	The simplest measure of variability, represented by the difference between the highest and lowest values in a frequency distribution.
208137092	Standard Deviation	A measure of variability that indicates the average difference between the scores and their mean.
208137093	Correlation	A relationship between variables, in which changes in one variable are reflected in changes in the other variable.
208137094	Normal Distribution	A bell-shaped curve, describing the spread of a characteristic throughout a population.
208137095	Correlation Coefficient	A number between -1 and +1 expressing the degree of relationship between two variables.
208137096	Inferential Statistics	Statistical techniques (based on probability theory) used to assess whether the results of a study are reliable or whether they might be simply the result of chance. Often used to determine whether 2 or more groups are essentially the same or different.
208137097	Random Sample	A sample group of subjects selected by chance (without biased selection techniques).
208137098	Representative Sample	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- variables such as age, income level, ethnicity, and geographical distribution.
208137099	Significant difference	Psychologists accept a difference between the groups "real", or significant, when the probability that it might be due to an atypical sample drawn by chance is less than in 5 in 100 (indicated by the notion p<.05)