chapter2

toc =Vocabulary=


 * Sample**- The small group of participants, out of the total number available, that a researcher studies.


 * Naturalistic observation**- Research method in which the pyschologist observes the subject in a natural setting without interfering.


 * Case study**- Intense study of a person or group.


 * Surveys**- Research method in which information is obtained by asking many individuals a fixed set of questions.


 * Longitudinal studie**s- Research method in which data is collected about a group of participants over a number of years to assess how certain characteristics change or remain the same during development.


 * Cross**-sectioinal study- An alternate approach to gathering data.


 * Correlation**- the measure of a relationship between two variables of sets of data.


 * Hypothesis**- An educated guess about the relationship between two variables.


 * Variables**- Any factor that is capable of change.


 * Experimental group**- Participants who are exposed to the independent variable.


 * Control group**- Participants who are treated the same why as the experimental group, except that they are not exposed to the independent variable.


 * Self-fulfilling prophecy**- involves having expectations about a behavior and then actiong in some way, usually unknowinglly, to carry out that behavior.


 * Single-blind experimen**t- An experiment in which the participants are unaware of which participants reveived the treatment.


 * Double-blind experiment**- An experiment in wich neither the experimenter nor the participants know which participants received which treatment.


 * Placebo effect**- A change in a patients illness or physical state that results solely from the patients knowledge and perceptions of the treatment.


 * Statistics**- A branch of mathematics that enables researchers to organize and evaluate the data they collect.


 * Descriptive statistics**- The listing and summarizing of data in a practical effient way.


 * Frequency distrubution**- A way of arranging data so that we know how often a particular score or observation occurs.


 * Normal curve**- A graph of frequency distribution shaped like a symmetrical, bell-shaped curve.


 * Central tendency**- A number that describes something about the average score of distribution.


 * Variance**- A measure of difference.


 * Standard deviation**- A measure of variability that describes an average distance of every score from the mean.


 * Correnlation coefficient**- Describes the direction adn strength of the relationship between two sets of variables.


 * Inferential statistics**- Methods used to determine whether research data suffort a hypothesis or whether results were due to change.

=**Section 1:**=

Psychologists have to first decide how to approach the issue they are going to research. Then psychologists conduct the research in one of a variety of waays to test a hypothesis, solve a problem, of confirm previous findings. Researchers begin their research by asking specific questions about a limited topic, Determining the validity of a claim, hypothesis, or theory and choosing a sample. Pyschologist use several research methods to accomplish their goals. These methods include naturalistic observation, case studies, surveys, and experiments.

=**Section 2:**=

The investigation of psychological issues is a painstaking process. Psychologists must reconize and resolve errors while doing research. An experimenter has expectations about a participants behavior and then acts in some way, usually unknowingly, to influence that behavior. In single-blind experiments the participants do not know which participants have received the treatment. When researchers evaluate the effects of drugs, they must always take into account a possible placebo effect.

=**Section 3:**=

Psychologists mst collect and evaluate evidence to support their hypothesis. Researches use discriptive statistics to organize data in a practical, efficient way. Discriptive statistics includedistributions of data, measures of variance and correlation coefficients. Researchers also useinferential statistics to make generalizations about the population from which the participants come.