Psych ch 2

an observation technique in which one person is studied in depth in the hope of revealing universal principles.

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.

in an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluation the effect of the treatment.

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

A type of research that is mainly statistical in nature. Correlation studies determine the relationship (or correlation) between two variables.

a study in which people of different ages are compare with one another.

the outcome factor; the variable that may change in response to manipulations of the independent variable

an experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.

The researcher allowing his or her expectations to affect the outcome of a study.

in an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable

An approach to research that relies on sensory experience and observation as research data

A summary chart, showing how frequently each of the various 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.

a testable prediction, often implied by a theory.

the perception of a relationship where none exists

the experimental factor that is manipulated; the variable whose effect is being studied.

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. Inferential statistics are often used to determine whether two or more groups are essentially the same or different.

research in which the same people are restudied and retested over a long period.

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores.

the middle score in a distribution; half the scores are above it and half are below it.

the most frequently occurring score(s) in a distribution

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.

a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean and fewer and fewer near the extremes.

a statement of the procedures used to define research variables. For example: human intelligence may be operationally defined as what an intelligence test measures.

effect experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

all the cases in a group being studied, from which samples may be drawn

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups.

a sample that fairly represents a population because each member has an equal chance of inclusion

the difference between the highest and lowest scores in a distribution

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances.

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 geographic distribution

A five-step process for empirical investigation of a hypothesis under conditions designed to control biases and subjective judgments.

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 (indicated by the notation p < .05)

a computed measure of how much scores vary around the mean score.

a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.

- an explanation using an integrated set of principles that organizes observations and predicts behaviors or events.