Principles of Assessments

Reliability: It is the level to which an assessment task produces resistant and firm results.The source or nature of the task should be precise to the students .When  it is set, and where there are multiple markers they should be discussed, and it is recomended to be used on some sample cases prior to be using used 'for real'. 

Validity: It refers how well a test what is supposed to be measured. An assessment demonstrates content validity when the criteria it is measuring aligns with the content of the job. Also, the extent to which that content is essential to job performance (versus useful-to-know) is part of the process in determining how well the assessment demonstrates content validity.

Authenticity: Authentic assessment aims to evaluate students' abilities in 'real-world' contexts. In other words, students learn how to apply their skills to authentic tasks and projects in real world.

Washback: It refers to the influence important tests have on classroom practices—in particular, the effects they have on teaching and learning.