This book covers the nature of measurement, the context that determines the uses of language tests, and the nature of the language abilities to be measured.
Various is the correct author for any book with multiple unknown authors, and is acceptable for books with multiple known authors, especially if not all are known or the list is very long (over 50).
If an editor is known, however, Various is not necessary. List the name of the editor as the primary author (with role "editor"). Contributing authors' names follow it.
Note: WorldCat is an excellent resource for finding author information and contents of anthologies.
It is an advanced resource book .It is amazing and useful for students and researchers who ready to finish his/her PHD program. Language Testing and Assessment is an important textbook to study and analyze the principles of language testing and assessment. How to analyze the validity, practicality , reliability, authenticity and wash back. How to argue all things concerned tests and evaluation of language and how to discriminate between students by using the normal curve and skewed distribution and all the things which acquire qualities of a good test , how to design a good test and it studies the four types of tests a placement, a diagnostic test ,achievement test, and proficiency test.