42 terms

AP Psychology Chapter Two

organized sets of concepts that explain phenomena
prediction of how two or more factors are likely to be related
repetition of the methods used in a previous experiment to see whether the same methods will yield the same results
independent variable
the factor that is changed or manipulated during an experiment
dependent variable
the outcome factor; the variable that may change in response to manipulations of the independent variable
all the cases in a group, from which samples may be drawn for a study
a subset of the population that participates in the study
random selection
choosing of members of a population so that every individual has an equal chance of being chosen
experimental group
the group that receives the experimental treatment or independent variable
control group
the group that does not receive the experimental treatment or independent variable
a research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process; establish cause and effect relationship
a research method that looks like an experiment BUT subjects are not randomly assigned to control and experimental groups; no cause and effect can be drawn
naturalistic observation
observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation
surveys and tests
obtain large samples of abilities, beliefs, or behaviors at a specific time and place
case study
an observation technique in which one person is studied in depth in the hope of revealing universal principles
random assignment
division of the sample into groups so that every individual has an equal chance of being put in any group or condition
confounding variable
a factor other than the independent variable that might produce an effect in an experiment.
operational definition
a description of the specific procedure used to determine the presence of a variable
experimenter bias
a phenomenon that occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained
demand characteristics
clues participants discover about the purpose of a study that suggest how they should respond
single blind procedure
research design in which participants don't know whether they are in the experimental or control group
double blind procedure
research design in which neither the experimenter nor the participants know who is in the experimental group and who is in the control group
a physical or psychological treatment that contains no active ingredient but produces an effect because the person receiving it believes it will
placebo effect
response to the belief that the IV will have an effect, rather than the IV's actual effect, which can be a confounding variable
consistency or repeatability of results
the extent to which an instrument measures what it is intended to measure
a branch of mathematics that psychologists use to organize and analyze data
descriptive statistics
numbers that summarize a set of research data obtained from a sample
frequency distribution
an orderly arrangement of scores indicating the frequency of each score or group of scores
central tendency
average or most typical scores of a set or research data or distribution; mean, mode, and median
the arithmetic average of a distribution
the most frequently occurring score in a distribution
the middle number in a set of numbers that are listed in order
the spread or dispersion of a set of research data or distribution; range, variance, standard deviation
the difference between the highest and lowest scores in a distribution
standard deviation
a measure of variability that indicates the average difference between the scores and their mean.
normal distribution
bell-shaped curve that represents data about how lots of human characteristics are dispersed in the population
percentile score
the percentage of scores at or below a certain score
correlation coefficient
a statistical index of the relationship between two things (from -1 to +1)
inferential statistics
statistics that are used to interpret data and draw conclusions
statistical significance
the condition that exists when the probability that the observed findings are due to chance is very low.
ethical guidelines
suggested rules for acting responsibly and morally when conducting research or in clinical practice