AP PSYCH - Scientific Method Unit

hypothesis

An educated guess or prediction that can be tested.

theory

a well-supported explanation of mental processes or behaviors through scientific methods and observations

overconfidence

Thinking you know more or can do more than you really can

operational definition

A clear explanation of how something is measured in a study

replication

Repeating a study to see if the results are the same.

case study

examining 1 individual or group in depth in hopes of revealing things that are true of us all

naturalistic observation

Watching people or animals in their natural setting without interfering

survey

Asking people questions to collect information about their thoughts or behavior

social desirability bias

when people answer questions in a way that makes them look good, not honestly

self-report bias

When people don’t give accurate answers about themselves, either on purpose or by mistake

sampling bias

When the group studied doesn’t fairly represent the whole population

random sample

A group chosen by chance where everyone in the population has an equal chance of being picked

population

The full group of people the researchers want to learn about.

correlation

relation between 2 variables, indicating how they change together

correlation coefficient

measure (-1 to +1) that quantifies the strength of the linear relationship between variables

single-blind procedure

experimental procedure where participants are ignorant (blind) about receiving treatment of placebo

double blind procedure

where both participants and researchers are ignorant (blind) about which participants have placebo/treatment

placebo effect

When people feel better just because they think they got treatment, even if it was fake

confounding variable

factor other than the one being studied that might affect the results

experimenter bias

When the researcher’s expectations influence the outcome of the study

quantitative research

Research based on numbers and data

qualitative research

Research based on descriptions, opinions, or observations

informed consent

When participants are told about the study and agree to take part

debriefing

Explaining the study to participants after it’s over, especially if there was deception.

mode

the value that appears most frequently in a data set

mean

arithmetic average of a data set

median

middle score in a data set when arranged from smallest to largest

standard deviation

measure of how much a score or value varies from the average of the data

normal/bell curve

graph that shows more clustered scores near center or mean and fewer scores near extreme ends

meta-analysis

a statistical procedure to summarize the results of multiple studies for strong conclusion

statistical significance

the results are unlikely to have happened by chance; they probably show a real effec

longitudinal

one group over a long period of time

cross-sequential

simultaneously gets data from different ages

cohort-sequential

common characteristics of different ages observed over time

positively skewed distribution

tail goes to positive side

negatively skewed distribution

tail goes to negative side

p-value and tests

1. amount of error

2. can never be 0 or 1

3. T-test, ANOVAs, MANOVAs

inferential statistics

use sample data to make generalizations and predictions about a larger population

coercion

participants cannot be conned, required, or excessively paid to participate. Subjects must always have the right to decline or withdrawal at any time

confidentiality

information about a subject during the course of study must remain anonymous

more significant results

smaller p-value means

descriptive statistics

measure of central intelligence (mean, median, mode, correlation coefficient, outliers, measure of variability)