assessment and evaluation are the terminal ends of all scientific inquiries. They need each other, and they support one another. They are also essential for the improvement of the subject or the person. 1. Assessment is done at the beginning of the inquiry, whereas evaluation is usually done at the end. 2. Assessment seeks to note down all data, both subjective and objective, while evaluation notes down whether there has been changes or improvements in the data. read more in here http://www.differencebetween.net/miscellaneous/difference-between-assessment-and-evaluation/

Evaluation is the analysis and use of data by teachers or a faculty to make judgments about student performance. Evaluation includes the determination of a grade or a decision regarding pass/fail for an individual assignment or a course. Assessment, on the other hand, is the analysis and use of data by students, teachers, a faculty or departments to make decisions about improvements in teaching and learning.

To my mind, they are basically synonyms, but you have specific collocations such as assessment centre (where you assess candidates whether they will cope well in a position in a company). Other meaning of assess is to estimate: a tax assessment