AP psychology unit 1 research methods

Placebo effect

A change in behavior caused by exception alone

Skewed distribution

A representation of scores that lack symmetry around their average value

Independent Variable(IV)

Manipulated by the experimenter

Mode

Most frequently occurring score. Bimodal-when 2 scores appear most frequently; multimodal- 3 or more scores

Control group

Not exposed to IV;they function as a comparison for evaluating the effectiveness to the factor being studied

Inferential statistics

Numerical data allow one to generalize- to infer from sample data the proximity of something being true of a population

Descriptive statistics

Numerical data used to measure and describe characteristics of groups; Includes measures of central tendency and measure of variation

Dependent Variable(DV)

Observation and measurement of the behavior or mental process of participants on an experiment

Theory

Organized explanation for data, gained through empirical processes

Overconfidence

Overestimate how correct our predictions and beliefs about ideas actually are

Correlation

Predict-designed to describe a relationship

Experimental group

Receives the independent variable

Normal curve

Represents a perfectly symmetrical distribution

Sampling bias

Sample not representative of the population or does not provide all the members of the population an equal chance to be chosen for the study

Representative sample

Sample that is representative or similar to the population as a whole

Median

Score that falls in the exact middle of the distribution; not sensitive to extreme scores or outliers

Operational definition

States precisely as possible what each variable means, including how it will be measured

Frequency distribution

Tables that contains data about how often certain scores occur or how many subjects fit into each category

Experimental bias

Tendency for researchers to unknowingly influence the results in an experiment

Hindsight Bias

Tendency to believe we could have predicted the outcome of an event after it already happened

Conformation bias

Tendency to selectively attend to info that is consistent with our viewpoint and ignore or minimize info that challenges our beliefs

Hypothesis

Testable and falsifiable prediction explaining the relationship between variables

Standard deviation

The average distance of each score from the mean

Culture

The enduring behaviors,ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next

Validity

The extent to which a test measures or predicts what it is supposed to

Debriefing

The post experimental explanation of a study, including, its purpose and any deceptions, to its participants

Critical Thinking

Thinking that examines assumptions, assesses the source,discern hidden values, evaluates evidence, and assesses conclusions

Statistical significance

A statistical statement of how likely it is that an obtained result occurred by chance

Informed consent

An ethical principle that research participants be told enough to enable them to choose whether they wish to participate

Confounding variable

Any difference present other than the IV between the two groups might effect the DV

Mean

Arithmetic average of a set of scores. Most affected by extreme scores known as outliers

Hawthorn effect

Being selected to be in a group, will affect, the performance of the group

Double-blind procedure

Both the research staff and participants are blind about whether the participants have received the IV, treatment or placebo

Naturalistic observation

Carefully and systematically watching humans or animal behavior as it occurs in the natural environment

Scatter plot

Correlation between two or more variables is illustrated on a graph

Experiment

Designed to determine cause and effect

Survey

Designed to discover the beliefs, opinions, and attitudes of a sample in order to draw conclusions of the population

Correlation coefficient

Determines the strength of the relationship between the variables

Range

Distance or spread between the highest and the lowest scores in a distribution

Random assignment

Ensures that each participant has an equal chance of being assigned to either the experiment or control group

Random sample

Every member of the population has an equal chance

Replication

Having future psychologists repeat the exact procedure

Case study

In-depth investigations of individuals or groups, allow for insight into rate behaviors and provides suggestions for future research

Population

Includes all members of a group that could be selected for research and to whom the results apply

Illusory correlation

Incorrect perception that two variables are related or an overestimation about the strength of a relationship