AP Psychology Unit 0

Institutional Review Board (IRB)

A committee at each institution where research is conducted to review every experiment for ethics and methodology.

double-blind procedure

A research strategy in which neither subjects nor experimenters know which subjects are in the experimental or control groups.

convenience sampling

Choosing a sample based on those who are easiest to access and readily available

qualitative measures

Data not recorded in numerical form; may be narrative or yes/no responses

correlational studies

Examine the relationship between variables, but DO NOT establish cause and effect

mode

The value that occurs most frequently in a given data set.

Institutional Animal Care and Use Committee (IACUC)

a committee to review animal research for ethics and methodology

case study

a descriptive technique in which one individual or group is studied in depth

naturalistic observation

a descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

bimodal distribution

a distribution with two modes - has 2 peaks

confounding variable

a factor other than the factor being studied that might influence a study's results

scatterplot

a graphed cluster of dots, each of which represents the values of two variables

statistical significance

a measure of how likely it is that a result is due to chance.

standard deviation

a measure of how much the values in a dataset deviate from the mean

experimenter bias

a phenomenon that occurs when a researcher's expectations or preferences about the outcome of a study influence the results obtained

operational definition

a precise description of the variables in research to allow for replication

positive correlation

a relationship between two variables in which both variables either increase or decrease together

representative sample

a sample that accurately reflects the characteristics of the population as a whole

random sampling

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

sample

a subset of the population

falsifiable

able to be disproven by experimental results

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate and they must agree to do so

random assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

experiment

can help establish causation; involves the use of independent variable(s) and random assignment

qualitative inferential data

describes qualities or characteristics

correlation coefficient

describes the strength and direction of the relationship between 2 variables (-1 to 1)

sampling bias

exists when a sample is not representative of the population from which it was drawn

informed assent

for research done on children, they must be told enough to enable them to choose whether they wish to participate and they must agree to do so

percentile rank

indicates the percentage of data points in a data set below a given value

structured interviews

interviews in which all applicants are asked the same set of standardized questions (example of a qualitative measure)

quantitative inferential data

is numerical

cross-sectional study

observe changes over time by studying people at each age you are interested in, all at once

normal distribution

produces a curve that is bell-shaped and symmetrical around the mean

likert scales

questionnaires that require individuals to indicate their degree of agreement or disagreement with a set of statements (example of a quantitative measure)

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

single-blind procedure

research design in which participants don't know whether they are in the experimental or control group

generalizable

research is able to be applied to the population as a whole; this is possible when a representative sample is used

68-95-99.7 rule

rule that describes what percentage of values fall within 1, 2, and 3 standard deviations of the mean

placebo

something which has a possible mental effect, but no physical effect

longitudinal study

studies changes over time; one group that is studied at each of the ages in question

self-report bias

systematic errors that can occur in self-report data because participants are unable or unwilling to answer accurately

negatively skewed distribution

tail extends to the left (has a few unusually small values)

positively skewed distribution

tail extends to the right (has a few unusually large values)

effect sizes

tells us the magnitude or strength of a relationship between variables or the difference between groups.

range

the difference between the highest and lowest scores in a distribution

control group

the group that does not receive the independent variable; used to establish a baseline for comparison

population

the group that is being studied as part of research; the people that can 'answer' the research question

experimental group

the group that receives the treatment or is exposed to the independent variable

median

the middle value in a data set

negative correlation

the relationship between two variables in which one variable increases as the other variable decreases

social desirability bias

the tendency for people to say what they believe is appropriate or acceptable

dependent variable

the variable that is expected to change as a result of the experimenters manipulations of the other variable; the 'then' part of the hypothesis

independent variable

the variable that is manipulated by the experimenter; the 'if' part of the hypothesis

mean

this is often called 'the average'; obtained by adding all of the values in a data set and dividing by the number of data points

quantitative measures

units of measure expressed in numerical terms

survey

using questionnaires to gather info about thoughts, opinions and behaviors

hypothesis

your prediction about the results of your research