Introduction:
When preparing for the UPSC exams, attempting previous years' papers can be extremely helpful. However, the decision to attempt them with an open book or under closed book conditions depends on various factors and needs to be carefully considered.

Open Book Conditions:
Attempting previous years' papers with an open book means having access to study materials, textbooks, and other resources during the examination. There are several advantages to this approach:

1. Enhanced Learning: Open book conditions allow candidates to refer to their study materials, which can help them gain a deeper understanding of the subject matter. It enables them to learn and reinforce concepts while attempting the questions.

2. Realistic Examination Scenario: UPSC exams are known for their vast syllabus and the need for comprehensive knowledge. Attempting previous years' papers with open book conditions replicates the real examination scenario, where candidates can refer to relevant resources to answer questions accurately.

3. Building Confidence: By attempting previous years' papers with open book conditions, candidates can gain confidence in their ability to find relevant information quickly and apply it effectively. This confidence can be invaluable during the actual examination.

Closed Book Conditions:
On the other hand, attempting previous years' papers under closed book conditions means relying solely on memory and understanding. Though this approach may seem challenging, it also offers certain benefits:

1. Assessment of Knowledge: Attempting previous years' papers under closed book conditions provides a true assessment of a candidate's knowledge and understanding of the subject. It helps identify areas of weakness and areas that require further study.

2. Time Management Skills: UPSC exams have strict time constraints, and candidates must learn to manage their time effectively. By attempting previous years' papers under closed book conditions, candidates can practice time management skills and develop strategies to tackle questions efficiently.

3. Improving Memory: Closed book conditions require candidates to rely on their memory and understanding, which helps in strengthening their recall ability. Regular practice under closed book conditions can enhance memory retention and recall during the actual examination.

Conclusion:
Both attempting previous years' papers with open book conditions and under closed book conditions have their own advantages. It is recommended to strike a balance between the two approaches. Candidates can initially attempt previous years' papers with open book conditions to enhance their understanding and learn new concepts. As they progress, they can gradually transition to attempting the papers under closed book conditions to assess their knowledge, improve time management skills, and enhance memory retention. Remember, regular practice and self-assessment are crucial for success in the UPSC exams.