Practice • Improve • Repeat
Complete guide for the UPSC ISS – Indian Statistical Service.
Every question below was asked in a real UPSC ISS interview, drawn from the transcripts of recommended candidates across the last year cycles, lightly generalised. Each carries a one line pointer, not a full answer, because the thinking is the preparation. Week 2 covered the machinery: the ISS officer’s work, the surveys, the indices, GDP, … Read more
Welcome back to Part 18 of Module 5, updated for the UPSC ISS 2026 to 2027 cycle. Part 17 taught us rates of change from tables. Today we learn accumulated areas from tables: Numerical Integration, and it all begins with one master equation, the General Quadrature Formula, also called the Newton Cotes Quadrature Formula. Numerical … Read more
Three stories dominate India’s data landscape as the 2026 interviews approach: Census 2027 is underway with its houselisting phase running right now and caste enumeration coming, the Digital Personal Data Protection Rules were notified in November 2025, and artificial intelligence has entered both the questions and the machinery of statistics. Real boards have asked about … Read more
Welcome to Part 17 and the opening of Module 5, updated for the UPSC ISS 2026 to 2027 cycle. With Modules 1 to 4 behind you, interpolation holds no fear. Now we enter the highest weightage block of the Numerical Analysis unit: calculus without calculators, beginning with Numerical Differentiation. Numerical differentiation evaluates the derivative of … Read more
ISS boards regularly ask candidates to explain statistical ideas in plain language: a p value to a layman, the difference between correlation and causation, why samples work at all. The transcripts prove the pattern: real candidates were asked for practical life examples of the normal distribution, everyday uses of the harmonic mean, which average best … Read more
India’s GDP is estimated by the National Statistical Office by measuring the value added of every sector of the economy, cross checked from the production, income and expenditure sides. On 27 February 2026, the NSO released an entirely new GDP series with base year 2022-23, replacing the 2011-12 base that had stood for over a … Read more
India measures prices and production through three headline indices: the Consumer Price Index for retail prices, the Wholesale Price Index for bulk trade prices, and the Index of Industrial Production for output. In February 2026 the CPI was rebuilt on a new base year of 2024, which makes this the single most interview relevant topic … Read more
The National Statistical Office runs the surveys that measure Indian life: the Periodic Labour Force Survey for employment, the Household Consumption Expenditure Survey for spending, the Annual Survey of Industries for the factory sector, and the Time Use Survey for how Indians spend their day. Real ISS boards have asked about every one of these, … Read more
An Indian Statistical Service officer designs and runs the surveys that measure India, builds the national accounts that produce GDP, compiles the price indices that track inflation, and serves as the statistical backbone of ministries across the Government of India. The service was constituted in 1961, and its cadre controlling authority is the Ministry of … Read more
Ten questions appear again and again across four years of UPSC ISS interview transcripts, from the opening introduction to the closing courtesy. If you can answer these ten honestly and calmly, you walk into Dholpur House already prepared for the spine of your interview. Day 7 closes Week 1 of our series. All week we … Read more