A sampling technique that often leads to biased studies because it consists or only available members of the population. This method is not recommended.

A method of gathering data in which a researcher applies a treatment to part of the population and then observes and measures the responses of interest of part of a population.

A sampling technique in which each member the population is assigned a number, a starting point is randomly selected, and sample members are chosen at regular intervals from the starting number.

The branch of statistics that involves using a sample to draw conclusions about a population. A basic tool in the study of inferential statistics is probability.

A harmless unmediated treatment given to subjects in an experiment; it is made to look like the real treatment.

A method of gathering data in which a researcher observes and measurements the characteristics of interest of part of a population but does not change existing conditions.

The subjects involved in an experiment.

The collection of all outcomes, responses, measurements, or counts that are of interest.

A method of gathering data that uses a mathematical or physical model to reproduce the conditions of a impractical, expensive, or dangerous situation of process.

A technique where the subject does not know whether he or she is receiving a treatment or placebo.

A numerical description of a population characteristic.

Subjects are paired up according to a similarity. One subject in the pair receives one treatment while the other subjects receives a different treatment.

The branch of statistics that involves the organization, summarization, and display of data.

Every member of the population has an equal chance of being selected.

Qualitative only. Data at this level are categorized using names, labels, or qualities. Mo mathematical computations can be made at this level.

Occurs when a subject reacts favorably to a placebo when in fact he or she has been given no medical treatment at all.

Data that are similar to data at the interval level, with the added property that a zero entry is an inherent zero. A ration of two data values can be formed so that one data value can be meaningfully expressed as a multiple of another.

Groups of subjects with similar characteristics.

A count of measures of the entire population.

A count or measure of a representative part of the population.

A subset of a population.

Consist of attributes, labels, or nonnumerical entries.

Every possible sample of the same size has the same chance of being selected.

Consist of information coming from observations, counts, measurements, or responses.

Repetition of an experiment using a large group of subjects to improve the validity of experimental results.

Subjects are divided into blocks with similar characteristics, and then within each block they are randomly assigned to treatment or control groups.

Neither the subject nor the experimenter knows if the subject is receiving a treatment or a placebo. The experimenter is informed after all the data have been collected.

A process of randomly assigning subjects to different treatment groups in an effort to obtain unbiased results.

A sampling technique used when the population falls into naturally occurring subgroups, each sharing similar characteristics; the populations is divided into groups and then all members of one or more groups are selected for the study.

A sampling technique used where it is important to have members from each segment or the population; the population is divided into subjects that share a similar characteristic and some members of each group are randomly selected for the study.

Occurs when an experimenter cannot tell the difference between the effects of different factors on a variable.

A method of gathering data which is an investigation carried out by asking people questions by interview, mail, or telegraph.

The difference between the results of sampling and those of the population.

The part of the population to which no treatment is applied in an experiment.

Subjects are assigned to different treatment groups through random selection.

Qualitative or quantitative data. Data at this level can be arranged in order, or ranked, but differences between data entries are not meaningful.

A numerical description of a sample characteristics.

Data that can be ordered, and you can calculate meaningful differences data entries. At this level, a zero entry simply represents a position on a scale; the entry is not an inherent zero.

Consist of numerical measurements of count.