CASA psych - methods

best fit line

a straight line on a scatterplot that best represents the data; it may or may not pass through some or all of the data points

case study

a research method which investigates a single subject in great detail

clinical observation

a diagnostic method in which a subject is watched for signs of mental illness

confounding variable

generally, something that affects the outcome of an experiment that had not been considered in the research design

control group

in an experiment, the subjects who are not subjected to the independent variable

correlation

a statistical relationship between two variables

correlation coefficient

the measurement of a statistical relationship between two variables

debriefing

giving research subjects a full explanation of the research at the end of the research project

dependent variable

what the experimenter measures at the end of an experiment

descriptive statistics

statistical information used to describe aspects of the data collected

double-blind

an experiment in which neither the experimenter or the subjects know which subjects are in the experimental or control groups

experiment

a research method in which a variable is manipulated in order to assess its effect on another variable

experimental group

in an experiment, the subjects who are subjected to the independent variable

generalization

the process of deriving a principle from a limited number of observations and applying more broadly

hypothesis

a prediction; an empirically testable proposition

illusory correlation

the perception of a relationship between variables where none really exists

independent variable

the variable manipulated by an experimenter

inferential statistics

methods that allow researchers to draw conclusions about a population from data derived from a small sample of the population

informed consent

voluntary agreement to participate in research by a subject who is aware of the risks and benefits of participating

mean

the arithmetical average of a set of numbers

median

the score that divides a distribution into two equal-sized halves

mode

the most common element in a set of data

naturalistic observation

a research method in which subjects are observed in their ordinary habitat

negative skew

a non-normal distribution with a long tail extending to the left has this

normal distirbution

also called Gaussian, this refers to a set of data whose graph is symmetrical and bell-shaped

null hypothesis

the statement that an experiment will find no difference between the experimental and control conditions

operational definition

a description of a variable in terms of the method in which it will be measured

percentile

the location of a score in a distribution such that its location describes the amount of the distirbution less than that score

placebo

an inert substance used with a control group in place of the active substance used with the experimental group, as, for example, in a drug test

population

all the members of a group friom which a sample may be drawn

negative correlation

a number between 0 and -1.0 that describes the relationship between two variables

positive correlation

a number between 0 and 1.0 that describes a relationship between two variables

positive skew

a non-normal distribution with a long tail to the right has this

random assignment

the process by which each member of the sample has an equal opportunity to be included in the experimental or control group

random sample

the process by which each member of the population has an equal opportunity to be included in the sample

range

in statistics, a measure of dispersion found by subtracting the smallest score from the largest in a distribution

replication

performing the essence of a research project again using different subjects

representative sample

this accurately reproduces the characteristics of the population from which it is drawn

sampling error

the extent to which a sample is not representative of the population

scatterplot

a method of graphing data involving two variables

single blind

an experiment in which the subjects, but not the experimenter, are unaware of which members are in the experimental or control groups

standard deviation

a measure of dispersion; the average distance from the mean of each data point

statistical significance

the degree to which a result cannot be attributed to chance

statistics

a branch of mathematics that uses data descriptively or inferentially to support scientific questions

survey

a research method in which members of a sample are asked about their opinions

theory

this organizes and summarizes observations and experiments and can be used to make predictions

critical thinking

its elements are: examine assumptions, discern bias, evaluate evidence, assess conclusions

scalable

a quality variables must have in a correlation; it means able to measured on a scale

false consensus

the tendency to overestimate the extent to which others share our beliefs

IRB

the body that must approve research projects in a university

case history

this could be a part of case study in which the clinician looks at the long-term experience of a patient

confederate

one who appears to be a participant in a study, but is actually working with the experimenter

confederate

examples of this are the "teachers" in Milgram's obedience studies or most of the participants in Asch's conformity studies

cross-sectional study

a research method in which the subjects belong to one of a number of different age-range groups

longitudinal study

a research method in which subjects are observed or tested over a long period of time - in some cases, over a lifetime

demand characteristic

any aspect of a research project that communicates to participants how they are expected to behave

evidence-based practice

using research results to inform clinical practice

descriptive research

methods of investigation that provide useful information about a phenomenon, but cannot be used to find correlations or cause-and-effect

empirical method

gaining information through observation, data collection, and logical reasoning

experimental bias

this occurs when the researcher's expectations or preconceptions affect the results of the research

external validity

the extent to which a research design actually reflects the real world situation it purports to address

external validity

Was Milgram's experiment an accurate reflection of the obedience expected of German soldiers? If not, his experiment can be said to lack ________________

internal validity

the extent to which changes in the dependent variable are the result of the independent variable

meta-analysis

a statistical method which allows a researcher to summarize results from many studies of a topic

placebo effect

this occurs when participant's expectations affect the outcome of a study, as, for example, when in a drug study those in the control group seem to exhibit the effects of the drug

participant bias

this occurs when subjects of a study alter their behavior according to how the think they should behave

third variable problem

occurs when a variable not considered in the research design affects the outcome of the research (i.e., a confounding variable)

hindsight bias

to claim after the fact that you could have predicted how an event occurred is evidence of this

sampling bias

this occurs when the process of choosing participants in a study is affected by prejudices or expectations of the researcher

5 terms for the way data in a study can be graphed when the data make a symmetrical graph

normal distribution, normal curve, bell curve, standard distribution, standard curve

trend line

another term for best fit line