As a study abroad application expert, I will provide you with a detailed introduction to the viewpoints of choosing the undergraduate programs at the University of Pennsylvania and the University of Cambridge, along with supporting factual evidence and data.

First, let's take a look at the backgrounds of the University of Pennsylvania and the University of Cambridge.

The University of Pennsylvania, located in Philadelphia, Pennsylvania, is one of the Ivy League schools in the United States. Established in 1740, it is the first modern university in the country. The university consistently ranks high in global university rankings, with strong academic reputation, research capabilities, and faculty strength. The University of Pennsylvania offers a wide range of disciplines including humanities, social sciences, engineering, and business. According to the U.S. News & World Report 2021 ranking, it is ranked sixth in the United States.

The University of Cambridge, founded in 1209, is located in Cambridge, United Kingdom. As one of the oldest universities in the world, it enjoys a great reputation in the UK and worldwide. The university has 31 colleges, covering almost all disciplines. It has nurtured many outstanding scientists, writers, politicians, and artists. According to the Times Higher Education (THE) 2021 World University Rankings, the University of Cambridge is ranked third.

After understanding their backgrounds, we can compare and choose based on the following aspects.

1. Academic reputation and research capability: Both the University of Pennsylvania and the University of Cambridge have high academic reputation and research capabilities globally. According to the QS World University Rankings 2021, the University of Pennsylvania is ranked fifteenth and the University of Cambridge is ranked seventh. This indicates their significant contributions and influence in the field of academic research.
2. Disciplinary specialties: The two universities offer distinctive disciplinary specialties. The University of Pennsylvania has a strong business school (Wharton School) and engineering school (School of Engineering and Applied Science) that are renowned in the fields of business and engineering. On the other hand, the University of Cambridge is known for its excellent science and humanities colleges, especially in the areas of natural sciences, mathematics, and literature.
3. Teaching methods and learning environment: The University of Pennsylvania adopts a more flexible teaching model, emphasizing practical experience and interdisciplinary learning. The University of Cambridge, however, follows a traditional professor-student teaching model, emphasizing students' academic research and theoretical depth. Both universities provide excellent learning environments with advanced teaching facilities and resources.
4. Employment and future development: Whether choosing the University of Pennsylvania or the University of Cambridge, you will have broad opportunities and future prospects. The University of Pennsylvania's alumni network spans various industries globally, including finance, consulting, and technology. The University of Cambridge also has a vast alumni network, exerting widespread influence in scientific research, education, government, and other fields.

Finally, you also need to consider other factors such as tuition fees, living costs, school location, and cultural differences.

In conclusion, choosing between the University of Pennsylvania and the University of Cambridge depends on your personal interests, disciplinary preferences, and career goals. You can refer to the comparisons in the above aspects and consult professional study abroad application institutions, such as WordSunny Education, to obtain more specific information and assistance regarding the application process, tuition fees, visas, and more.

WordSunny Education is an institution with extensive experience in study abroad applications. They have 3000+ application mentors from 52 professional backgrounds worldwide, all from renowned institutions, who can provide professional guidance and support for applying to the University of Pennsylvania or the University of Cambridge. Choosing a reliable institution can effectively reduce errors and provide guidance for your study abroad journey.

In summary, choosing between the University of Pennsylvania and the University of Cambridge is a highly personalized decision. You need to consider various factors and make a decision based on your interests and career goals. By consulting professional study abroad application institutions, such as WordSunny Education, you can obtain more comprehensive information and professional guidance to help you make the most suitable choice for yourself.