When evaluating the Tang Dynasty, it can be carried out from the following aspects:

1. Teaching level: You can understand Tang's teaching methods and effects, including students' evaluation and feedback, as well as teaching achievements and honors.

2. Academic ability: You can learn about Tang's academic level and research achievements, including published papers, scientific research projects undertaken and academic awards won.

3. Professional attitude: You can understand Tang's work attitude and professionalism, including professional ethics, work responsibility, teamwork spirit and so on.

4. Innovative spirit: You can learn about Tang's innovative thinking and practice in his work, including the innovation of teaching methods and scientific research ideas.

5. Social services: You can learn about Tang's performance in social services, including participation in public welfare activities and contributions to society.

It should be noted that evaluating a person is a complex multi-dimensional process, which requires comprehensive consideration of many aspects. At the same time, evaluating a person also needs to be based on objective facts and evidence to avoid subjective prejudice and misunderstanding.