What tools can compare all text of submitted assignments semantically after paraphrasing and detect plagiarism?
You can try using Sentence-Bert, original paper here: https://arxiv.org/abs/1908.10084
Github link here: https://github.com/UKPLab/sentence-transformers
It is very easy to use since I had used that before and it took me just several minutes learning how to use it.
The usage is fairly simple, you generate embedding for each assignment, and compare the cosine similarity between each pair of assignments embeddings.
Then you can manually look at the ones that have very high cosine similarity.
The Github repository descriptions said: This framework provides an easy method to compute dense vector representations for sentences, paragraphs, and images. The models are based on transformer networks like BERT / RoBERTa / XLM-RoBERTa etc. and achieve state-of-the-art performance in various task. Text is embedding in vector space such that similar text is close and can efficiently be found using cosine similarity.