PSTATS CHPTR 2

Definition of Statistics

Branch of science which deals with the collection, presentation, analysis and interpretation (CoPAI) of data.

Nature of Statistics

Aids in decision making

Nature of Statistics

Summarizes data for public use

Fields of Statistics

Statistical Methods of Applied Statistics

Fields of Statistics

Statistical Theory of Mathematical Statistics

Statistical Methods of Applied Statistics

Refer to procedure and techniques used in the CoPAI of data.

Descriptive Statistics

Comprised with methods concerned with the collection, description and analysis of a set of data w/o drawing conclusions.

Descriptive Statistics

The main concern is to simply describe the data

Descriptive Statistics

Conclusions apply only to the data on hand.

Inferential statistics

Comprise those methods concerned with making predictions or inferences about a larger set of data

Inferential Statistics

The main concern is not merely describe but to predict and make inferences based on the information gathered

Inferential Statistics

Conclusions are applicable to a larger set of data which a data on hand is only a subset.

Statistical Theory of Mathematical Statistics

Deals with the development and exposition of theories that serve as the bases of statistical methods

Population

Is a collection of all the elements under consideration in a statistical study

Sample

A part or subset of the population from which the information is collected

Parameter

Numerical characteristic of the population

Statistic

Numerical characteristic of the sample

Steps in Statistical Inquiry

1. Define the problem

2. Formulate the research design

3. Collect data

4. Code and analyze the collected data

5. Interpret the results

Variable

Is a characteristic or attribute of persons or objects which can assume different values or labels

Measurement

Process of determining the value or label of a particular variable for a particular experimental unit

Discrete Variable

Infinite number of values; measured by counting or enumeration

Continuous Variable

Infinitely many values corresponding to a line interval

Qualitative Variable

Categorical response

Quantitative Variable

Numerical values

Nominal Level (Classificatory Scale)

Is the weakest level of measurement where numbers or symbols are used only for categorizing subjects

Ordinal Level (Ranking Scale)

Contains the properties of the nominal level. Variables may be ranked in low-high manner.

Interval Level

Had the properties of ordinal and nominal level.

Interval Level

Must have a common and constant unit of measurement

Ratio Level

Contains all the properties of the interval level

Ratio Level

Has a true zero point

Primary Source

Data measured by the researcher that published it

Secondary Source

Any republication of data by other agency

Internal Data

Information that relates to the operations and functions of the organization collecting the data

External Data

Information that relates to some activity outside the organization collecting the data