This is one of the most important decisions one has to make while planning to take the Civil Services exam. There are 25 optionals one has to choose from. I assume you know the list and the combinations not allowed to be taken. If not, kindly visit the UPSC website www.upsc.gov.in and look up in general > examinations conducted by upsc > civil services (main) exam.
Since there is uncertainty regarding the scheme of the Civil Services (prelims) exam and UPSC may introduce the Civil Services Aptitude Test from next year onwards, I am going to concentrate on the 2 optionals one has to choose for the Mains.
While choosing my optionals, I started the process by eliminating all those optionals which I wouldn’t choose anyways. So Animal Husbandry & Veterinary Science, Electrical Engineering, Civil Engineering, Medicine, Geology, Statistics etc were eliminated.
I was left with a list of 6-7 optionals from which I had to choose 2. This decision has to be based entirely on your INTEREST and APTITUDE.
To help you decide, go through the syllabus prescribed for each optional you have short listed and try to further shorten the list. When I saw the syllabus for Mechanical Engineering (since I am a mechanical engineer) I took the decision to leave it out as I felt it was very vast and I could not manage it with General Studies and another optional. But if you are confident that you have good command over a subject, it shouldn’t matter even if the syllabus is vast. I was not interested in engineering anyways, and it was a back-up for me since I knew I would take the civil services exam. So the decision to leave it out was easy for me to make.
The reason why INTEREST should be the foremost criterion is because the minimum period of time you would be studying for the CSE is 2 years- from 1 year before the prelims and another 1 year, the duration of the exam. If you find your optional boring then it is going to be difficult to study it for a long duration (both number of months as well as number of hours in a day). So go with what interests you.
Also, APTITUDE has to be one of the important factors as what interests you will not necessarily be easy to study for you. For example, I always liked Mathematics in school and had good scores in it, but the level of maths in the CSE is certainly beyond my abilities.
After going through the syllabus, kindly refer the previous 5 years’ mains exam question papers for the given subject. The papers are easily available on the net. Do not assume by looking at the questions whether the optional seems to be easy or difficult. This is because even if the questions seem to be easy, the answer you would have to write in the exam might require a very good grasp over the subject, which isn’t that easy for any given optional.
By this time, I am sure you would be down to at most 3 optionals. It would now be a question of either this or that between 2 of them. To make the decision, kindly get a basic book for each of the two. This you can easily find out from someone who has prepared for the CSE with that optional. For example, the book I read for psychology was Introduction to Psychology- Morgan and King. I immediately realised it was the right optional for me. So I guess you would also be able to make that decision.
There are some other factors which many aspirants consider- overlap between optional and GS syllabus, availability of study material, toppers’ optionals, trend, etc. I am not in a position to comment on the availability of study material as I do not have much idea about other optionals. But yes, overlap between optional and GS syllabus can also be a good reason, provided interest and aptitude have been taken care of.
But factors such as toppers’ optionals, trend, average marks last year, etc are to be avoided at any cost. Such decision-making is completely illogical. What person A has studied is entirely based on his/her interest and aptitude which is not necessarily same as yours. The average scores, etc keep on changing every year for a given optional. For example, average scores in pub ad mains were well over 300 in 2008 but the situation was completely reversed in 2009. Who knows what might happen in 2010. Moreover, average is nothing but a calculated number. What you score is entirely independent of the average.
At the end of the day, whichever optional you choose, the decision has to be made entirely by YOU. You are the one who has to study for the exam, not your parents, teachers, friends, etc. Do seek advice from others, but make the decision yourself. Coaching classes very often discourage candidates from choosing certain optionals. It is a heavily biased opinion which they offer. Moreover, it’s easy to see that they discourage taking any optional which they do not teach in their institute. Kindly guard against it.
I have tried to give an outline of the method I followed while choosing the optionals. There might be many other factors. Always remember, my advice may be one of the many you might seek, but the decision has to be entirely yours.