Innovative research methods: The doctoral thesis can adopt new research methods or technologies to analyze and discuss the research contents in depth. These methods or techniques can be new experimental design, data processing methods, statistical analysis methods, etc. Or they can be improvements or optimizations of existing methods.
Expand the research field: doctoral thesis can expand the research scope of subject field and explore and explore new research fields. These fields can be interdisciplinary research fields or frontier research directions.
Perfecting existing theories: Doctoral dissertations can improve or perfect existing theories and put forward new theories or models. These improvements can be based on new research data or experimental results, or they can be criticism and revision of existing theories.