mean

The average in a set of numbers

medianThe average in a set of numbers

mode

Most frequently re-occuring number in a set of numbers

standard deviationUsed to show and measure the

variation in data

histogram

A graph that shows the frequency between two things

operational definition

The process of defining a measurement that isn't necessarily measurable--it may be vague and unclear before you create this.

theory

A list of ideas that are used to explain predictions and to make predictions

hypothesisAn educated guess on what the outcome will be that

supports the theory

researchThe actual collection of the data being tested. The test of

the hypothesis

descriptive research

Used to describe behavior and characteristics of the population. Usually Naturalistic Observation, Case Studies, and Surveys

naturalistic observation

The process of observing and classifying, not explaining, behavior of people in a

natural setting (at home, parks, a mall). The people are being observed without

interference between the observer and the one being observed. The bad thing about it is observer bias, it's time consuming, and you

don't have control over the environment.

observer bias

When the researcher them self alters or changes the results of the study. For example, a teacher studying

differences in math skills between boys and girls might spend more time teaching boys because he/she believes that boys are better at math.

case study

Kind of the same as naturalistic observation, except is has a deeper study on a certain topic with fewer people (for example, health.) You usually can't replicate these and

because of the small amount of people, it takes away generalization.

surveyUsed to get large amounts of data in a short

amount of time, either though an interview or a questionnaire.

These are very inexpensive, however, people may lie because they know they're a part of an experiment, and it doesn't represent the entire population. It also

leads to more advanced research.

correlational research

The process of examining how variables are naturally related to the real world. This only shows the relation between two

things, not how they were caused (Cannot determine causality, only correlation. For example, you can't say less sleep causes more stress or vice versa). This is good because you can explore relations in a natural environment, and provide a

base for future experiments.

correlational coefficients

The numerical relationship between the variables. The scale goes from -1.00 to +1.00. An example of positive correlation (0 to +1.00) is time spent studying and grades. An example of negative Correlation (0 to -1.00) is the time spent playing

video games and grades.

scatterplotsThe visual representation on the variables and how they

correlate with each other.

experimental research

This is the manipulation of one variable to examine the effect on the second variable.

experimental group

The group of people being experimented on, or those who are receiving the treatment.

control group

The group not being experimented on, or those who are not receiving the treatment.

placebo effect"The sugar pill". A group of people

receive a pill (or any other forms) that they continue to take to cure whatever needs to be cured, and their minds are tricked into actually thinking it works, so they believe that it's actually doing what

is said to be doing however it's not.

double-blind study A medical study in which both the groups participating

and the researchers are unaware of when and what the experimental medication or procedure has been given.

The experimenters don't know who is in what group and the subjects don't know which group they are in. This

helps fix the placebo effect.

independent variable

The variable that is manipulated or changed by the researcher.

dependent variable

The variable that is measured. It is something that depends on other factors. For example, a

test score.

confounding variable

AKA the extraneous variables, these variables cannot be controlled by the researcher and could influence any change in the Dependent Variables (DV).

random sampling

This requires that every person in the population has an equal chance of being selected. The goal

of this is to generalize findings from the sample to the population.

random assignment

This requires that every member of the sample has an equal likelihood of being assigned to the

experimental group. It balances out the unknown factors, making them equally likely to appear in

both groups.

statistical significance

You are very sure that the statistic is reliable--the data has shown there's a measurable difference between the

experimental group and the control group.

replication

If the experiment can be repeated and have the same or nearly the same results.

5 ethical criteria for human research

1. Informed consent2. Right to Withdraw

3. Freedom from Harm4. Debriefing

5. Confidentiality

informed consent

The process of telling research participants what will happen during an experiment and requiring them to sign a form stating they understand the

requirements. Researchers are allowed to lie in this part of a study.

freedom from harm

The ethical requirement that research participants suffer no long-lasting

damage as the result of participating in a study.

right to withdraw

The ethical requirement that research participants be allowed to leave a study

whenever they choose.

debriefing

Explanation of an experiment after the study is over, includes telling participants the purpose of the

study and any deceptions.

confidentialityThe right for research participants identity and personal

information to be kept private.

ethics

Established by the A.P.A., guidelines that outline what is acceptable and unacceptable for

treatment of participants in research studies.

descriptive statistics

Process of organizing numerical data to describe the basic features. The basis for quantitative analysis of results. Includes mean, median, mode, standard

deviation, and range.

inferential statistics

The process of analyzing statistical data to determine if the results are significant and can be generalized to the larger population.

population

A larger group of people or animals from which a sample is drawn.

sampleA set of subjects drawn from a specific

population

skewed distribution

The result when a few extreme values (outliers) cause the entire distribution of data to move too far to one

side of the mean.

validityThe extent to which an experiment measures what it is

supposed to measure.

reliability

The extent to which a test yields consistent results when replicated.

illusory correlation

seeing a corollary relationship when there actually is none.

measures of central tendency

measures of variation

hindsight bias

The feeling of "I knew it all along!", when someone incorrectly assumes they knew the outcome of a situation after already finding out the results.

overconfidenceThe tendency to overestimate how easy something

might be or how long a task might take.

perceiving order in random

eventsHumans' tendency to see patterns where there

are none--such as in flipping a coin.