The 5 Principles of Language Assessment

The first one of the 5 principles  is PRACTICALITY. This principle regards how easy a test is to administer taking into account that tests should be easy to administer, not excessively expensive, they should be planned and applied within appropriate time limits (not time consuming), and they have a scoring process that is specific and time efficient.
         
The second principle that the author points out is the RELIABILITY.  A reliable test needs to be consistent and dependable. There are some subdivisions of reliability: Student-Related Reliability, rater Reliability, test Administration Reliability and, test Reliability. To sum up, reliability  is the degree to which an assessment tool produces stable and consistent results.
          
Another principle is VALIDITY.  It refers to how well a test measures what it is supposed to measure.  Validity is also devided in different categories such as:  Face Validity, exams like Toelf that measures English and it is valid in every university in the world, and consequential validity, gives information about the benefits of dangers after taking the exam.

AUTHENTICITY regards if the items are as contextualized, if the topics and situations are interesting and enjoyable, and if the tasks are real-world tasks.

Finally, Brown mentiones the fifth priciple, WASH BACK. It includes the effects of an assessment on teaching and learning prior to the assessment itself, that is on preparation for the assessment: Informal performance assessment is by nature more likely to have built-in wash back effects because the teacher is usually providing interactive feedback. Formal tests can also have positive wash back, but they provide no wash back, if the students receive a simple letter grade or a single overall numerical score. Classroom test should serve as learning devices through which wash back is achieved.

Wash back enhances a number of basic principles of language acquisition: intrinsic motivation, autonomy, self confidence, language ego, interlanguage, and strategic investment, among others. Wash back implies that students have ready access to the teacher to discuss the feedback and evaluation he has given.