Data
Consists of information coming from observations, counts, measurements, or responses.
Statistics
The science of collecting, organizing, analyzing, and interpreting data in order to make decisions.
Population
The collection of all outcomes, responses, measurements, or country that are of interest.
Sample
A subset of a population.
Parameter
A numerical description of a population characteristic.
Statistic
A numerical description of a sample characteristic.
Descriptive Statistics
The branch of statistics that involves the organization, summarization, and display of data.
Inferential Statistics
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.
Qualitative Data
Consists of attributes, labels, or nonnumerical entries.
Quantitative Data
Numerical measurements or counts.
Nominal Level of Measurement
Qualitative only. Data at this level are categorized using names, labels, or qualities. No mathematical computations can be made at this level.
Ordinal Level of Measurement
Qualitative or quantitative. Data at this level can be arranged in order, but differences between data entries are not meaningful.
Interval Level of Measurement
Quantitative only. The data can be ordered and you can calculate meaningful differences between data entries. At this interval level, a zero entry simply represents a position on a scale; the entry is not an inherent zero.
Ratio Level of Measurement
Similar to the data at the interval level, with the added property that a zero entry is an inherent zero. A ratio of two data values can be formed so one data value can be expressed as a multiple of another.
Inherent Zero
An inherent zero is a zero that implies "none". For instance, the amount of money you have in a savings account could only be zero dollars. In this case, the zero represents no money-- it is an inherent zero. On the other hand, a temperature of 0 degrees