Chapter 1 The Scientific Method & Descriptive Research Methods

statistics

a branch of mathematics used by researchers to organize, summarize, and interpret data

extraneous variable

a factor or variable other than the ones being studied that, if not controlled, could affect the outcome of an experiment; also called a confounding variable

variable

a factor that can vary, or change, in ways that can be observed, measured, and verified

placebo

a fake substance, treatment, or procedure that has no known direct effect

negative correlation

a finding that two factors vary systematically in opposite directions, one increasing as the other decreases

positive correlation

a finding that two factors vary systematically in the same diection, increasing or decreasing together

statistically significant

a mathematical indication that research results are not very likely to have occurred by chance.

experimental method

a method of investigation used to demonstrate cause-and-effect relationships by purposely manipulating one factor thought to produce change in another factor

correlational coefficient

a numerical indication of the magnitude and direction of the relationship (the correlation) between two variables

operational definition

a precise description of how the variables in a study will be manipulated or measured

survey

a questionnaire or interview designed to investigate the opinions, behaviors or characteristics of a particular group

correlational study

a research strategy that allows the precise calculation of hoe strongly related two factors are to each other

sample

a selected segment of the population used to represent the group that is being studied

representative sample

a selected segment that very closely parallels the larger population being studied on relevant characteristics

scientific method

a set of assumptions, attitudes, and procedures that guide researchers in creating questions to investigate, in generating evidence, and in drawing conclusions

natural experiment

a study investigating the effects of a naturally occurring event on the research participants

theory

a tentative explanation that tries to integrate and account for the relationship of various findings and observations

hypothesis

a tentative statement about the relationship between two or more variables; a testable prediction or question

double-blind technique

an experimental control in which neither the participants nor the researchers interacting with the participants are aware of the group or condition to which the participants have been assigned

case study

an intensive study of a single individual or small group of individuals

main effect

ant change that can be directly attributed to the independent or treatment variable after controlling for other possible influences

placebo effect

any change attributed to a persons beliefs and expectations rather than an actual drug, treatment or procedure; expectancy effect

practice effect

any change in performance that results from mere repetition of a task

psuedoscience

fake or false science that makes claims on little or no scientific evidence

demand characteristics

in a research study, subtle clue or signals expressed by the researcher that communicate the kind of response or behavior that is expected from the participant

control group or control condition

in an experiment, the group of participants who are exposed to all experimental conditions, except the independent variable; the group against which changes in the experimental group are compared

experimental group or experimental condition

in an experiment, the group of participants who are exposed to all experimental conditions, including the independent variable

meta-analysis

involves combining and analyzing the results of many research studies on a specific topic in order to identify overall trends

random selection

process in which subjects are selected randomly from a larger group such that every group member ahs an equal chance of being included in the study

descriptive research methods

scientific procedures that involve systematically observing behavior in order to describe the relationship among behaviors and events

critical thinking

the active process of minimizing preconceptions and biases while evaluating evidence, determining the conclusions that can reasonably be drawn from evidence, and considering alternative explanations for research findings or other phenomena

dependent variable

the factor that is observed and measured for cahnge in an experiment; thought to be influenced by the independent variable; also called the outcome variable

random assignment

the process of assigning participants to experimental conditions so that all participants have an equal chance of being assigned to any conditions or groups in the study

independent variable

the purposely manipulated factor thought to produce change in an experiment; also called the treatment variable

naturalistic observation

the systematic observation and recording of behaviors as the occur in their natural setting

replicate

to repeat or duplicate a scientific study in order to increase confidence in the validity of the original findings

empirical evidence

verifiable evidence that is based upon objective observation, measurement, and/or experimentation