How do we gather and analyze data? Exam 1

Random sample

a subset of individuals (a sample) chosen from a larger set (a population). Each individual is chosen randomly and entirely by chance, such that each individual has the same probability of being chosen at any stage during the sampling process, and each subset of k individuals has the same probability of being chosen for the sample as any other subset of k individuals.

Population

a summation of all the organisms of the same group or species, who live in the same geographical area, and have the capability of interbreeding.

Single-blind study

a test or experiment in which information about the test that might lead to bias in the results is concealed from the tester, the subject, or both until after the test.

Experiments

an orderly procedure carried out with the goal of verifying, refuting, or establishing the validity of a hypothesis.

Statistically significant (or statistically reliable)

used to describe the overall consistency of a measure. A measure is said to have a high reliability if it produces similar results under consistent conditions.

Independent variable

represent the inputs or causes, or are tested to see if they are the cause.

Dependent variable

represents the output or effect, or is tested to see if it is the effect.

Mean

the sum of a collection of numbers divided by the number of numbers in the collection.

Burden of proof

a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge.

Theory

a contemplative and rational type of abstract or generalizing thinking, or the results of such thinking.

Case history/study

a descriptive, exploratory or explanatory analysis of a person, group or event.

Normal distribution (or normal curve)

a function that tells the probability of a number in some context falling between any two real numbers.

Control group

a group designed to minimize the effects of variables other than the single independent variable.

Experimental group

a group of subjects that are exposed to the variable of a control experiment.

Survey

a method for collecting quantitative information about items in a population.

Correlation

a mutual relationship or connection between two or more things.

Hypothesis

a proposed explanation for a phenomenon.

Naturalistic observation

a research tool in which a subject is observed in its natural habitat without any manipulation by the observer.

Placebo

a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient.

Double-blind study

an experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment; a double-blind procedure is used to guard against both experimenter bias and placebo effects.

Random assignment

an experimental technique for assigning subjects to different treatments (or no treatment). The thinking behind random assignment is that by randomizing treatment assignment, then the group attributes for the different treatments will be roughly equivalent and therefore any effect observed between treatment groups can be linked to the treatment effect and is not a characteristic of the individuals in the group.

Correlational study

explores relationships between variables.

Experimenter bias

subjective bias towards a result expected by the human experimenter.

Replicable result

the ability of an entire experiment or study to be reproduced, either by the researcher or by someone else working independently.

Descriptive statistics

the discipline of quantitatively describing the main features of a collection of data, or the quantitative description itself.

Median

the numerical value separating the higher half of a data sample, a population, or a probability distribution, from the lower half.

llusory correlation

the phenomenon of perceiving a relationship between variables (typically people, events, or behaviors) even when no such relationship exists.

Representative sample

the population is divided into strata and a random sample is taken from each stratum.

Falsifiable

the trait of a statement, hypothesis, or theory whereby it could be shown to be false if some conceivable observation were true.

Mode-

the value that appears most often in a set of data.