WHAT IS STATISTICS?

WHAT IS STATISTICS?

Statistics has both plural and singular senses.

In its plural sense, it refers to numerical facts that are systematically collected and analyzed, as in the responses in a questionnaire.

In the singular sense, it refers to the scientific discipline consisting of theory and methods for processing numerical information that one can use when making decisions in the face of uncertainty.

In both senses, the term Statistics refers to quantities computed from numerical information as such, statisticians are involved with methods of data collection, data summarization or presentation, data analyses as well as communicating the results of its analyses or data interpretation hence, Statistics may also be defined as the branch of science that deals with the collection, presentation, analysis, and interpretation of quantitative data.

DATA MANAGEMENT

Data collection – refers to the process of gathering or obtaining information, measurements, observations, etc.

Data presentation – refers to the organization of collected data into meaningful forms such as the use of tables, graphs, or charts so that logical and statistical conclusions can be derived from the collected measurements.

Data analysis – pertains to the process of extracting from the given data meaningful or relevant information from which numerical description can be formulated.

Data interpretation – refers to the task of drawing conclusions from the analyzed data which normally involves the formulation of forecasts or predictions about larger groups based on the data collected from small groups

BRANCHES OF STATISTICS

Descriptive Statistics – is concerned with data organization and presentation without drawing conclusions or inferences beyond the data.

Inferential Statistics – is concerned with drawing generalizations beyond the data collected provided that the data collected is a part of a large set of items.

BASIC TERMS

Universe – is the set of all entities under study
Variable – is the attribute of interest observable/measurable of each entity in the universe
Population – is the set of all possible values of the variable
Sample – a subset of the population
Parameters – are numerical measures that describe the population of interest

VARIABLE

It typically takes on more than one value of the monthly weight gain (or loss) for an individual which changes from month to month. Data obtained from these variables may be broadly classified as either quantitative or qualitative.

QUANTITATIVE VARIABLE

- Takes on numerical values and is otherwise known as numerical data.

- Sizes are meaningful. - Answer questions such as “how much” or “how many”. - Have actual units of measure. - Examples are height, weight, household size, number of nuts, and distance traveled.

QUALITATIVE VARIABLE

- Do not strictly take on numerical values although numeric codes may de develop from the values. - Answer questions “What kind”. - Either be ordered or non-ordered. - Examples are gender, occupation, taste, income data group, brand, and color.

DISCRETE AND CONTINUOUS DATA

Quantitative data may be further classified into discrete or continuous types.
Discrete data can be counted, assuming only a countable number of values. Examples are ages to the nearest year, number of nuts cracked, and weight of leaves
Continuous data are those that can be measured. Examples are height, weight, yield, IQ

MEASUREMENT

Is how one assigns a value to a trait, an attribute, or a characteristic such as sex, weight, religion, etc.
Is a basis for determining the statistical tool to use.
Arranged in chronological order from lowest to highest.

FORMULAS BEING USED