Statistics Vocabulary

Randomized Block Design

A commonly used experimental design in which subjects with similar characteristics are divided into groups, and then within the groups, randomly assigning subjects to treatment groups.

Descriptive statistics

A major branch of statistics that involve the organization, summarization, and display data

Inferential Statistics

A major branch of statistics that involves using a sample to draw conclusions about a population.

Survey

A method of data collection most often carried out on people by asking them questions mostly done by interview, mail, or telephone.

Census

A method of data collection that is a count or measure of an entire population.

Simulation

A method of data collection that uses a mathematical or physical model to reproduce the conditions of a situation sometimes with the use of computers. This method allows you to study situations that are impractical or even dangerous to create in real life.

Observational study

A method of data collection where a researcher observes and measures characteristics of interest of part of a population, but does not change existing conditions.

Experiment

A method of data collection where a treatment is applied to part of a population and responses are observed. Another part of the population may be used as a control group, in which no treatment is applied.

Parameter

A numerical description of a population characteristic.

statistic

A numerical description of a sample characteristic.

Systematic Sampling

A sampling technique in which each member of the population is assigned a number and then sample members are selected at regular intervals. (For instance, every 3rd member)

Random sample

A sampling technique in which every member of the population has an equal chance of being selected.

Convenience Sampling

A sampling technique that consists only of available people. This type of sampling can lead to biased studies.

Cluster Sampling

A sampling technique that is used when the population falls into naturally occurring subgroups, each having similar characteristics, and all the members in one or more(but not all) of the groups are selected

Stratified Sampling

A sampling technique used when it is important to have members from each segment of the population. The members are divided into two or more different subsets that share a similar characteristic. A sample is then selected from each of the subsets.

Qualitative Data

A type of data set that consists of attributes, labels, or non-numerical entries.

Quantitative Data

A type of data set that consists of numerical measurements or counts.

Sample

A type of data set that is a subset, or part, of a population.

Population

A type of data set that is the collection of all outcomes, responses measurements, or counts that are of interest

Ratio

Data at this level is quantitative only. Comparisons of two data values can be formed so that one data value can be meaningfully expressed as a multiple of another. Also, a zero entry is an inherent zero.

Ordinal

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

Interval

Data at this level quantitative only. This data can be ordered, and meaningful differences between data is entries can be calculated. A zero entry simply represents a position on a scale; the entry is not an inherent zero.

Statistics

The science of collecting, organizing, analyzing, and interpreting data in order to make decisions

Confounding variables

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

Data

consists of information coming from observations, counts, measurements, or responses

Nominal

Lowest level of data measurement that is qualitative only. Data at this level of measurement are categorized using names, labels, or qualities. No mathematical computations can be made at this level.