What is data in statistics?

Statistics is defined as the science of Collecting, Organizing, Summarizing, Presenting, Analyzing, and Interpreting the Data as well as deriving valid conclusions and making reasonable decisions on the basis of this analysis.

Statistical approaches

Descriptive statistics and is used to analyze a collection of data without assuming any underlying structure for such data.

Inferential statistics works on the basis of a given structure for the observed data and involves hypothesis testing to draw conclusions about a population when only a part of the data is observed.

What is data?

It is the individual pieces of factual information recorded, and it is used for the purpose of the analysis process.

This is a collection of facts, such as numbers, words measurements, observations, or just descriptions of things.

These are units of information, often numeric, that are collected through observation.

This is defined as facts or figures, or information that’s stored in or used by a computer.

Types of Data

Data collection

In Statistics, data collection is a process of gathering information from all the relevant sources to find a solution to the research problem.

Method of Collection of data

1. Primary source collection

A. Quantitative collection methods

• It is based on mathematical calculations using various formats like close-ended questions, correlation and regression methods, mean, median or mode measures.
• This method is cheaper than qualitative data collection methods.
• It can be applied in a short duration of time.

B. Qualitative collection methods

• It does not involve any mathematical calculations.
• This method is closely associated with elements that are not quantifiable.
• This includes interviews, questionnaires, observations, case studies, etc.
• There are several methods to collect this type.

Observation method: The observation method is used when the study relates to behavioral
science. This method is planned systematically. It is subject to many controls and checks.
The different types of observations are:

• Structured and unstructured observation
• Controlled and uncontrolled observation
• Participant, non-participant and disguised observation

Interview method: The method of collecting data in terms of oral or verbal responses. It is
achieved in two ways, such as

• Personal Interview – In this method, a person known as an interviewer is required to ask questions face to face to the other person. The personal interview can be structured or unstructured, direct investigation, focused conversation, etc.
• Telephonic Interview – In this method, an interviewer obtains information by contacting people on the telephone to ask the questions or views orally.

Schedule method: This method is similar to the questionnaire method with a slight difference. The enumerations are specially appointed for the purpose of filling the schedules. It explains the aims and objects of the investigation and may remove misunderstandings if any have come up. Enumerators should be trained to perform their job with hard work and patience.

Questionnaire Method: In this method, the set of questions are mailed to the respondent.
They should read, reply and subsequently return the questionnaire. The questions are
printed in a definite order on the form. A good survey should have the following features:

• Short and simple
• Should follow a logical sequence
• Avoid technical terms
• Should have good physical appearance such as colour, quality of the paper to attract the attention of the respondent.

2. Secondary source collection

• Secondary data is collected by someone other than the actual user. It means that the information is already available, and someone analyses it.
• This includes magazines, newspapers, books, journals, etc.
• It may be either published or unpublished data.

Published data

• Research articles,
• P.HD. Thesis and Dissertations
• National and International journals
• Government publications, Public records
• Historical and statistical documents
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