ISS Series 1: Tips and Strategy for ISS Exam by AIR 7 Sujit Padhan

ABOUT ME

My name is Sujit Padhan. I secured All India Rank (AIR) 7 in Indian Statistical Service (ISS) Examination, 2020. It was my first attempt.

I am a resident of Jampali village under Melchhhamunda Police Station of Bargarh District in Odisha. It is a very small village with population less than 1000.

I finished Class X at Jawahar Navodaya Vidyalaya (JNV), Sambalpur. From there, I got selected for free IIT-JEE coaching by Dakshana Foundation. I completed my intermediate (+2) from JNV Ranga Reddy (Hyderabad), Telangana along with IIT-JEE preparation. Then, I graduated in Civil Engineering from IIT Kharagpur. From there I got placed at CRISIL Limited where I worked for 21 months. Soon after that, I pursued MSc in Applied Statistics and Informatics from IIT Bombay.

ABOUT INDIAN STATISTICAL SERVICE (ISS) EXAMINATION

ISS exam is conducted every year by UPSC for recruitment to Junior Time Scale of Indian Statistical Service (ISS) in the Ministry of Statistics and Program Implementation (MoSPI). It is a Group A Central Civil Service (CCS).

ELIGIBILITY

Age Limits

For ISS Exam – 2024, a candidate must have attained the age of 21 years and must not have attained the age of 30 years on 1^st August, 2024 i.e he/she must have been born not earlier than 2^nd August, 1994 and not later than 1^st August, 2003. There is upper-age relaxation for candidates belonging to OBC, SC, ST, PwD and ex-servicemen.

Minimum Educational Qualification

The actual statement from Official Notice for ISS Exam, 2024 is: "A candidate for the Indian Statistical Service must have obtained a Bachelor's Degree with Statistics/Mathematical Statistics/Applied Statistics as one of the subject or a Master's degree in Statistics/Mathematical Statistics/Applied Statistics from a University."

The following note is also added in this year's notification:

NOTE 4: For Indian Statistical Service Examination, the study of Statistics as a component of a multidisciplinary course for one or two semesters should not be considered as eligibility for admission to the Indian Statistical Service Examination in terms of the existing educational qualification prescribed for the Examination. The study of Statistics should be in all the years of Bachelor Degree Course.

EXAMINATION PATTERN

The exam is conducted in two stages – Written examination and Personality Test/Interview. 

Stage 1 - Written Examination

The medium is English only. It is generally conducted in the month of June or July. In 2024, it will be conducted from 21st June to 23rd June. 

The exam is held for 3 days (Friday to Sunday) with two papers on each day. The various subjects/papers are:

Subject	Type	Total Marks	Time Duration
General English	Subjective	100	3 hours
General Studies	Subjective	100	3 hours
Statistics I	Objective	200	2 hours
Statistics II	Objective	200	2 hours
Statistics III	Subjective	200	3 hours
Statistics IV	Subjective	200	3 hours

Stage 2 - Personality Test/Interview

Candidates are shortlisted for Personal Interview to be held at UPSC, New Delhi based on the marks obtained in the Written examination. The number of such candidates is generally 2.5 to 3 times the number of vacancies available that year.

HIGHEST AND CUT-OFF MARKS

Highest Marks

The marks of Toppers in last five years are:

Year	Name	Written (1000)	Interview (200)	Total (1200)
2023	Nikhil Singh	610	106	716
2022	Astitva Ranjan Srivastava	556	124	680
2021	Amit Kumar	546	122	668
2020	Nipun Jain	536	133	669
2019	Harshit Agrawal	528	116	644

Cut-off Marks

The marks (out of 1200) of the last recommended candidate from each category in last five years are:

Year	General	EWS	OBC	SC	ST
2023	640	616	562	517	477
2022	608	542	535	498	340
2021	641	571	588	537	358
2020	567	534	538	489	363
2019	589	561	536	466	316

Wherever two or more candidates have secured equal aggregate marks in ISS Examinations, the tie(s) have been resolved in accordance with the principles approved by the Commission as under:

1. (i)  Candidates getting more marks in the total of the four Economics/Statistics papers of 800 marks plus viva voce of 200 marks may be ranked higher for the service; and

2. (ii)  Where marks vide (i) above are also equal, candidates senior in age may be ranked higher.

I have left out PwD because there are various sub-categories within PwD and the cut-off marks are different for them.

MY MARKS INFORMATION

Subject/Paper	Marks
General English (100)	53
General Studies (100)	25
Statistics I (200)	139.18 (All Time Highest)
Statistics II (200)	150.00
Statistics III (200)	53
Statistics IV (200)	56
Personality Test (200)	124
Total (1200)	600

DETAILED STRATEGY

I started my preparation for ISS Exam, 2020 in January 2020. It was my final semester at IIT Bombay. I studied for 2-3 hours a day and was not consistent with the preparation. I was thinking of appearing ISS Exam, 2020 to get a feel of how the exam was.

I had to return to my home in March due to COVID-19. By April, I got an idea that the exam would be held in September or October. Then, I decided to prepare for the exam seriously. I studied 4-5 hours a day.

The notification was released on 10^th June, 2020. There were 47 vacancies available for ISS and nought for IES (Indian Economic Service). I realised that it was a one-time opportunity for me. Since the number of seats (in ISS) was 50% more than normal, I somehow inferred that the situation would be pretty bad in 2021. And that is the case. There are only 11 vacancies available in 2021.

I had no intention of appearing for RBI exam or any other exam in 2020. Also, there was not much work at home. So, I gave my full attention to the preparation of ISS Exam, 2020. I had almost all the materials in soft copy format and that helped me a lot. Now, I dedicated 6-7 hours a day. From then, I increased my study hours by one hour every month and in September and October I studied for 9-10 hours a day.

Let me tell you about the subject-wise strategy:

General English

General English is the first paper in ISS Exam. The paper is same for both ISS and IES. It is a subjective paper of 100 marks with a duration of 3 hours. The general format is as follows:

It contains an essay question carrying 30 marks. There are 5 options available and you have to choose one among them. After analysing the previous years’ question papers (including 2020 and 2021), I have come up with the following important topics:

• Women Empowerment

• News media, Social media, Digital platforms and new-age technology

• Environmental pollution, Global warming and Sustainable development

• Education

• Constitutional Rights and Duties

• Regulation of sports bodies

• Agricultural revolution and economic growth

I read about these topics from various articles and essays. I followed the tips given by UPSC CSE 2017 topper, Anudeep Durishetty regarding the format of writing an effective essay.

The second question is on précis (summary) writing. Here, you have to make a summary of the given passage (about 600-750 words) in about one-third of the original length. It is also of 30 marks.

For this I referred to Precis Writing by R Dhillon. There are many paragraph there for practice.

I had allotted one hour each to essay writing and précis writing. But while writing the summary, I liked it so much that I answered this one by taking sufficient time. Initially, I went through the paragraph twice, then wrote the précis in the rough and finally on the answer sheet. I took 15-20 minutes more here than required and therefore, I could not write the conclusion of essay properly. I suggest you to not make this mistake. Please do not give excess amount of time to only one question.

The third question is on Paragraph writing. Here you have to write a paragraph in about 200 words on any one of the given five quotes/idioms. It is of 10 marks.

For Paragraph writing, I went through the previous years’ questions and got an idea it. I went through paragraph writing on about 50 idioms which I thought were important. I also made points on these topics.

The fourth and fifth questions are on sentence making. The fourth one is using given words and the fifth one is using given idioms/phrasal verbs respectively. Each of these questions are of 10 marks each. I generally read novel/fiction during my spare time and this helped me a lot here. Also, I followed “From Plinth to Paramount” book.

The last question is on sentence correction. It has 10 sub-parts carrying one mark each. “From Plinth to Paramount” helped me in practising this section as well.

General Studies

General Studies is conducted from 2 pm to 5 pm on the first day. The paper is same for both ISS and IES. It is a subjective paper of 100 marks with a duration of 3 hours. It has four parts – History, Geography, Economy and Polity. Each part has 5 sub-parts/questions carrying 5 marks each.

While looking at the scores of previous years’ toppers, I found that they score around 25-30 out of 100 in General Studies. I thought that I have a scope here. If I could score more than fifty here, then I would have less burden on the statistics papers. 

I really hoped I would score more than 50 in this papers as I had answered all 20 questions. Now I realise that my expectation was too high. The highest score (among selected ISS candidates) was 34 and I scored 25.

I rectified the mistake I had committed in the General English paper. During preparation, I had allotted 7-8 minutes for answering a question in General Studies. I wrote the answers as fast as I could during the examination and every few minutes I checked if I had sufficient time left for answering all questions. I was in a flow and answered all the 20 questions.

The general trend in History section was – 3 questions from Modern India and one each from Medieval and Ancient History. This trend, however, was defied in 2021 with 2 questions each from Ancient and Medieval History. Some important topics are:

• Ancient History – Indus valley civilisation, Vedic period, Buddhism, Jainism, Maurya Dynasty, Gupta Dynasty

• Medieval History – Mughal empire, Bhakti and Sufi Movements, Temple architecture, Delhi Sultanate

• Modern India – European trading companies, Social and educational reformers in 19^th Century, Sepoy Mutiny, Gandhian philosophy and movements, World Wars I and II, Transfer of Power, Integration of India, Wars with China and Pakistan

For History, I referred to the old NCERT books of Class XI and XII.

Some important topics in Geography are:

• Conservation of forest and wildlife

• Climate change

• Air pollution and water conservation

• Food security

• Urbanisation

• Demography

• Energy sources

• Rivers and mountain ranges of India

• Industrial revolution

• Natural disasters and their causes

For Geography, I referred to the old NCERT book of Class X and new NCERT books of Class XI & XII.

Most of the questions in Economy are from current affairs. Some important topics are:

• Agricultural acts and schemes

• Banking sector

• GDP, inflation and employment

• Union budget

• Demographic dividend and human development

• Women empowerment

• Health-care system

• Finance commission and recommendations

• GST and demonetisation

• New technology

For economy, I went through the monthly reports/magazines by Vision IAS. This helped me in covering current affair part of Geography and Polity as well. I recommend you to follow news for a year. For 2024, you can start taking note of the events occurring from July 2023.

For Polity, I referred to specific topics of M Laxmikanth. I got an idea about these topics looking at the previous question papers. Some important topics in Polity are:

• Indian Constitution

• Fundamental rights and duties

• 73^rd and 74^th Constitutional Amendment Acts

• 42^nd Constitutional Amendment Act

• Indian judiciary – Powers of Supreme Court and High Courts

• Election commission and electoral system

• Parliament, Legislation, Lok Sabha, Rajya Sabha

• Powers and Functions of President, Prime Minister, Governor, Attorney-General, Solicitor General, Comptroller & Auditor General

• Multinational governing bodies – SAARC, UN, G7, BIMSTEC

• Sustainable Development Goals

Objective Papers

Statistics I is conducted from 9 am to 11 am and Statistics II from 2 pm to 4 pm on the second day. Both the papers are MCQ type with 80 questions (negative marking), 200 marks and a time duration of 2 hours each. Statistics I has four parts – Probability, Statistical Methods, Numerical Analysis and Computer Application & Data Processing – each having equal weightage. Statistics II has three parts - Statistical Inference & Hypothesis Testing, Linear Models and Official Statistics. There are 45 questions from Statistical Inference & Hypothesis Testing, 15 from Linear Models and 20 from Official Statistics.

I have been solving MCQs for a decade – during IIT-JEE preparation days, at IIT Kharagpur and IIT Bombay and while preparing for IIT-JAM. So, in the initial days, I would solve few objective questions to get a hang of the ISS preparation. Even during the peak of preparation, I would spend an hour or two in practising objective questions to break the monotonicity of serious preparation.

I have scored the highest marks in Statistics I (139.18 out of 200) and Statistics I & Statistics II combined (289 out of 400). These probably are the highest scores in their respective categories since the introduction of objective papers in 2016.

For Probability, I referred to VK Rohatgi. But when I went through “Fundamentals of Mathematical Statistics” (FMS), I realised that Rohatgi was not so much required. For subsequent practice and revisions, I referred only to FMS for Probability, Statistical Methods and Statistical Inference & Hypothesis Testing. For Decision Theory (Loss function), Casella & Berger is good.

For Numerical Analysis, the book by Rao V Dukkipati is good. But there are some mistakes in the book. Please keep this in mind while practising from the book.

For Computer Application and Data Processing, I have heard that the book by Reema Thareja is very good. But, I did not look for it after unsuccessfully searching in the nearest book-store for few days. Instead, I referred to “Fundamentals of Computer” by E Balagurusamy. This is also a good book. There are certain topics which are not covered in the book. For those topics, I googled and found some relevant slides/PDFs.

I had taken Design of Experiments as an optional subject in Statistics IV. So, ANOVA and comparison tests were covered in that. Some other topics of Linear Models were also covered while preparing for Econometrics (Statistics III). We were taught Statistical Modelling in Semester 4 at IIT Bombay. The remaining topics – estimable functions, generalised inverse etc. - were covered there.

For Official Statistics, I referred to MoSPI (Ministry of Statistics and Program Implementation) website and its Annual Report (2019-20). I gathered information about various types of Consumer Price Indices (CPIs) and Sustainable Development Goals (SDGs) from newspapers/monthly magazines.

There was not much problem in managing time for Statistics II. For Statistics I, I had heard that Numerical Analysis part was lengthy and answering all the questions would be difficult. So, I made a strategy to tackle this problem. I allotted the following amount of time for various parts of Statistics I:

• Probability – 1.5 minutes per question (Total 30 minutes)

• Statistical Methods – 4 questions in 5 minutes (Total 25 minutes)

• Numerical Analysis – 2 minutes per question (Total 40 minutes)

• Computer Application and Data Processing – 2 questions per minute (Total 10 minutes)

• OMR Filling and last minute changes – 15 minutes

I solved ISS Exam papers of 2016-2018 in this manner and this helped me in managing time at the actual exam.

Statistics III

Statistics III is conducted from 9 am to 12 pm on the third day. It is a subjective paper with 200 marks and a time duration of 3 hours. There are total 8 questions in the paper. First two are compulsory and out of the remaining 6, you have to answer 3. Each question carries 40 marks.

Mark distribution for the first two questions (compulsory) is generally as follow:

• Econometrics – 30 marks (15+15)

• Sampling Techniques – 25 marks (10+15)

• Time Series – 15 marks

• Index Numbers – 10 marks

From the remaining 6 questions, there are two questions each from Econometrics, Sampling Techniques and Applied Statistics (Time Series + Index Numbers). Since, one has to select three among these, candidates used to leave either Econometrics or Time Series without missing much. But looking at 2021 papers, it seems that this strategy would fail. There was only 15 marks from Index Numbers (from the whole 8 questions). Also, 40 marks from the compulsory part (50% of it) seemed to be from Time Series.

This was the toughest paper for me in the sense that I had no significant edge over other candidates in this paper. I found the Simultaneous Linear Equations (after the Rank and Order Conditions part) a bit difficult and there was similar problem with Spectral Density part of Time Series. Thankfully, there was not much problem in the exam as there were questions from other parts and I could leave the questions from these sections without losing any marks. I answered one question each from the three broad divisions from the six optional questions.

Statistics IV

Statistics IV is conducted from 2 pm to 5 pm on the third day. It is a subjective paper with 200 marks and a time duration of 3 hours. There are 7 parts in it each carrying 100 marks. You have to choose exactly 2 parts/subjects. In each part, there are five compulsory questions carrying 10 marks each. There are also four 25-mark questions among which you have to answer two questions.

I chose Computing with C & R and Design of Experiment (DoE) in this paper. I was expecting to score good marks in the Coding part as the previous year questions were relatively easy for me. They were pure coding questions. There were occasional questions on Zero Sum Game, but were rare and could be skipped. But in 2020 (the year I appeared the exam), the situation was different. Almost all the questions from Computing with C & R required statistical knowledge and that too from Multivariate Analysis, Operations Research (Paper IV topics which I had ignored) and the Numerical Analysis part which was not in the syllabus. This posed a threat to me. On first look, I could not answer any question from this section. I took deep breaths for few moments and started working on Design of Experiment. Thankfully, I could answer the questions. I took 2 hours and answered the DoE part. In the remaining one hour, I answered around 30-40 marks from Computing with C & R.

I consider this as a narrow escape with DoE coming to the rescue. I suggest you to consider the worst case scenario before appearing for the exam.

Personality Test/Interview

Date - 20^th July 2021 (Afternoon)

Board – Dr. TCA Anant

Duration – 15-17 min

Medium - English

Interview Marks - 124/200

I reached Delhi two days prior to the Interview. The next day I carried out a dry run from the hotel to UPSC Bhavan. I did this to get a familiarity of the route and reach the premise on time on the day of interview. I was relaxed after this.

I reached UPSC Bhavan on 20^th July, 2021 around 12:30 pm. The candidates were allowed to enter UPSC premise at 1 pm. After the security check up, we were given kits regarding COVID-19 appropriate behaviour. The package consisted of hand-gloves, sanitiser, face mask, face shield. We were made to wear these things. All our personal masks, sanitisers were deposited in the locker-room. Then, we were ushered into a hall where document verification was carried out.

The interviews started at 2 pm. There were three boards for ISS interview. Six candidates were interviewed by each board. I was interviewed second in my group. After waiting for 20 minutes, I was escorted to the interview hall. I had to wear face mask and shield during the interview. No pen/paper was allowed inside.

The interview panel consisted of Chairperson Dr. TCA Anant (CP), Madam 1 (M1), Madam 2 (M2) and the other Sir (SR). When I took my seat after greeting them, they first confirmed with me about my career path as it was unusual (From Civil Engineering to Finance to Statistics).

The interview continued as below:

CP: What was your role at CRISIL Limited?

Me: Briefed him about my role

CP: Why did you switch to Statistics instead of pursuing MBA after your job?

Me: I have a love for numbers and I like analysing data from my childhood. In spare time, I do personal analysis. I have been doing this for a decade. This has helped me in improving myself. I want to implement the same on the job. Also, I want to help the poor and rural people of India by socio-economic planing and policy formulation. I believe ISS to be the best platform where I can showcase my helping nature and passion for statistics.

M1: Why did you take a job at CRISIL after pursuing Civil Engineering from IIT Kharagpur?

Me: Very few core companies visited the campus. I applied to various non-core companies and got selected at CRISIL.

M1: So, you completed your MSc recently. Tell us what all subjects did you study there?

Me: Statistical Inference, Regression Analysis, Multivariate Analysis, Linear Models, Time Series Analysis.........

M1: (i) What is Regression Analysis?

(ii) Describe Least Squares Method.

(iii) What are the components of Time Series?

(iv) Define Moving Average.

(v) Differentiate between Seasonal and Cyclic variations.

(vi) What are complementary goods?

Me: I fumbled a couple of times while answering these questions. I feel that I did not give satisfactory answers to some questions.

SR: Tell me about Ratha Yatra.

Me: Ratha Yatra is an annual festival associated with Lord Jagannath. It is celebrated in Odisha. The most famous Ratha Yatra is held at Puri. The deities Lord Jagannath, Maa Subhadra and Lord Balabhadra visit their Mausi’s place, Gundicha Temple.It is celebrated for nine days in the Hindu month of Ashadha. Today is the last day of the festival and is known as Bahuda Yatra.

(My eldest brother, Sudam Dada, suggested me to prepare for this question as it was very much expected)

SR: Who was Shri Chaitanya?

Me: Shri Chaitanya was a Vaishnavite in the 15^th-16^th centuries. He was a Krishna (an incarnation of Lord Vishnu) devotee and was a prominent figure in Bhakti movement in eastern India (predominantly in Odisha and Bengal).

S: Very good.

Me: Thank you, Sir.

M2: Can you tell us about the prasad at Jagannath Temple, Puri?

Me: The prasad at Jagannath Temple is known as Abadha. This is also called Chhappana Bhoga as 56 different dishes are included in the prasad.

It is also famous for the way in which it is prepared. The various pots are stacked one on the top of another and are ignited. Usually the heating should start from the bottom (Bottom up). But in the case, the pot at the top gets warm first and the others get warm in a top-down manner.

M2: What are your views on Artificial Intelligence?

Me: Artificial Intelligence is the future of automation. It is a good servant and bad master. If we use it for the betterment of the humanity, the world would achieve great heights. On the other hand, if it is used for destruction, it would not take much time to annihilate the planet.

CP: (Looked at the wall clock) Your interview is over.

Me: Thank you, Sir. Thank you, Mams. Thank you, Sir.

BOOKS/MATERIALS RECOMMENDATION

General English

1. Essay Notes by Anudeep Durishetty AIR 1 (UPSC CSE 2017)

2. Arihant 151 Essays by SC Gupta

3. Precis Writing by R Dhillon

4. From Plinth to Paramount by Neetu Singh

General Studies

1. Old NCERT History Books of Class XI and XII

2. Old NCERT Geography Book of Class X

3. New NCERT Geography Books of Class XI and XII

4. Indian Polity by M Laxmikanth

5. Monthly Current Affairs by Vision IAS

Objective Papers

1. Fundamentals of Mathematical Statistics by Gupta and Kapoor

2. Numerical Methods by Rao V Dukkipati

3. Fundamentals of Computers by E Balagurusamy

4. Statistical Inference by Casella and Berger

5. Design and Analysis of Experiments by Douglas C Montgomery (Chapter 3)

6. Linear Models by Searle and Gruber (Chapter 5)

7. MoSPI Annual Report

8. MoSPI Website

Statistics III

1. Sampling Techniques by William G Cochran

2. Basic Econometrics by Damodar N Gujarati

3. Shalabh Sir’s (IIT Kanpur) Lecture Notes on Sampling Theory and Econometric Theory

4. Fundamentals of Applied Statistics by Gupta and Kapoor (Chapters on Time Series and Index Numbers)

5. Introduction to Time Series and Forecasting by Brockwell and Davis

Statistics IV (Design of Experiments)

1. Fundamentals of Applied Statistics by Gupta and Kapoor (Chapters on Analysis of Variance and Design of Experiments)

2. Design and Analysis of Experiments by Douglas C Montgomery

Please do not follow more than two books on the same topics. Otherwise, it may lead to confusion.

CONCLUDING REMARK

I quote my favourite shloka from Shrimad Bhagwat Geeta to conclude the discussion:

"कर्मण्येवाधिकारस्ते मा फलेषु कदाचन"

This loosely translates to: “Give your best without worrying about the result.”

SIMILAR ARTICLES

• https://sujittravels.blogspot.com/2023/06/study-logs-during-upsc-iss-exam.html

• https://sujittravels.blogspot.com/2021/11/interview-transcripts-of-recommended.html