Q.Trace briefly the origin and growth of statistics, and name its two main modern branches.

The history of statistics explains its name and why it later became a rigorous science rather than mere record-keeping.

Statistics began as State record-keeping of population, land and revenue, then grew into a science when it combined with the theory of probability.

Origin. The word statistics comes from the Latin status, the Italian statista and the German statistik, all connected with the State. In its earliest form statistics was literally the 'science of the State' — rulers collected data on population, land, wealth and military strength chiefly to assess taxes and to raise armies. In India, Kautilya's Arthashastra (c. 4th century BCE) describes a systematic census of population and economic activity, and the Ain-i-Akbari of the Mughal era records detailed land-revenue and population statistics.

Growth. From administrative record-keeping, statistics became a rigorous discipline when it joined the theory of probability, developed from the 17th century through the study of games of chance. Probability enabled statistics to move beyond describing collected data to drawing reliable inferences about a whole population from a sample and measuring the uncertainty of those inferences. In the 19th and 20th centuries statistical methods spread into economics, business, the sciences, medicine, agriculture and industry.

Two modern branches.

• Descriptive statistics — collecting, organising, summarising and presenting data (averages, dispersion, tables, graphs); the focus of a Class 11 course.
• Inferential statistics — using a sample to draw conclusions about a larger population, resting on the theory of probability.

A frequent slip is confusing the two branches — descriptive statistics summarises data that has actually been collected, whereas inferential statistics generalises from a sample to a whole population. Do not describe both as merely 'collecting data'.