Introduction:
Studying previous years' papers can be a valuable strategy for UPSC aspirants to understand the changes in the assessment approach of the UPSC regarding the practical implications and societal relevance of psychological research studies. By analyzing the questions asked in previous years, candidates can gain insights into the evolving trends and patterns followed by the UPSC.

Identifying changes in the UPSC's approach:
Studying previous years' papers can help in identifying the changes made by the UPSC in assessing the practical implications and societal relevance of psychological research studies. Some key points to consider include:

1. Question types: Analyzing the previous years' papers can provide an understanding of the types of questions asked by the UPSC. Look for questions that specifically ask about the practical implications and societal relevance of psychological research studies. This will help in identifying any changes in the focus of the UPSC.

2. Weightage: Observe the weightage given to questions related to practical implications and societal relevance. If there is a significant increase or decrease in the number of such questions, it indicates a change in the UPSC's approach towards assessing this aspect of psychological research studies.

3. Keywords and phrases: Pay attention to the keywords and phrases used in the questions. If there is a shift in the language or emphasis on certain terms related to practical implications and societal relevance, it suggests a change in the UPSC's evaluation criteria.

4. Scoring pattern: Analyze the scoring pattern of questions related to practical implications and societal relevance. If there is a change in the marking scheme or the way answers are evaluated, it indicates a shift in the UPSC's approach towards assessing these aspects.

5. Interdisciplinary approach: Look for questions that require integration of psychological research with other disciplines such as sociology, anthropology, or public administration. If there is an increase in such questions, it implies that the UPSC is emphasizing the interdisciplinary application of psychological research in practical and societal contexts.

Conclusion:
Studying previous years' papers can provide valuable insights into the changes in the UPSC's approach towards assessing the practical implications and societal relevance of psychological research studies. By analyzing the question types, weightage, keywords, scoring pattern, and interdisciplinary approach, candidates can better prepare themselves for the current trends and expectations of the UPSC.