Myers Psychology for AP Unit 2 - Statistics

Hindsight bias

the tendency to believe, after learning an outcome, that one would've foreseen it

Critical thinking

thinking that does not blindly accept arguments and conclusions. Rather it examines assumptions, assesses the source, discerns hidden values, evaluates evidence, and assesses conclusions

Humility

an awareness of our own vulnerability to error and an openness to surprises

Theory

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

Hypothesis

a testable prediction, often implied by a theory

Operational definition

a carefully worded statement of the exact procedure used in a research study

Replication

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

Case study

a descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles

Naturalistic observation

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

Survey

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

Sampling bias

a flawed sampling process that produces an unrepresentative sample

Population

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

Random sample

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

Correlation

a measure of the extent to which two variables change together, and thus how well either variable predicts the other

Correlation coefficient

a statistical index of the relationship between two variables (from -1.0 to +1.0)

Scatterplot

a graphed cluster of dots, each which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables

Illusory correlation

the perception of a relationship where none exists

Experiment

a research method in which a researcher manipulates one or more factors to observe the effect on some behavior or mental process

Experimental group

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

Control group

in an experiment, the group NOT exposed to the treatment

Random assignment

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between groups

Double-blind procedure

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether have received the treatment or the placebo

Placebo effect

experimental results caused by expectations alone

Independent variable

the experimental factor that is being manipulated

Confounding variable

a factor other than the independent variable that might produce an effect in the experiment

Dependent variable

the outcome factor

Validity

the extent to which a test or experiment measures what it is supposed to

Descriptive research method

Conducted through case studies, naturalistic observation, or surveys to observe and record behavior

Correlational research method

Conducted through collecting data on two or more variables to detect naturally occurring relationships; to assess how one variable influences the other

Experimental research method

Conducted by manipulating one or more variables to explore cause effect

Descriptive statistics

numerical data used to measure and describe characteristics of groups

Histogram

a bar graph depicting a frequency distribution

Mode

the most frequently occurring score in a data set

Mean

the average of the scores in a data set

Median

the middle score in a data set

Skewed distribution

a representation of scores that lack symmetry around their average values

Range

the difference between the highest and lowest scores in a distribution

Standard deviation

a computed measure by how much scores vary around the mean score

Normal curve

a symmetrical, bell-shaped curve that describes the distribution of many types of data

Inferential statistics

numerical data that allow one to generalize--to infer from sample data the probability of something being true of a population

Statistical significance

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

Culture

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

Informed consent

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

Debriefing

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