The passage looks to be a part of literary piece and it is written in past tense

Selection tests

The aim of a selection test is to select the most suitable candidates for a particular course of study or for a profession. This is important when there are a limited number of vacancies. These tests are competitive by nature and we need to rank the students on the basis of their performances. Thus we compare the performances of one candidate with those of another. These tests should, therefore, discriminate the students well.
To achieve discrimination, we need to include the test items of a wide range of difficulty level. The most challenging test items will adequately discriminate the good from the weak.
The test paper should reflect the purpose for which selection is made. We should consider the profile of the selected individual at the beginning of test construction. For instance, if we are to select persons for the post of translator or correspondent assistant to the managing director or a group of students to follow English special degree or individuals for highly diplomatic post in the country, each category will have a distinctive set of profile-features. These specified skills should be identified at the beginning and based on them the test paper should be constructed. If oral component is important as for a personal assistant of a company, the test should include an oral component as well. Once the specified skills are determined, evaluation is made against this criterion. Thus our evaluation is criterion-based.
Since the test paper is not based on the course objective, the content validity has no any relevance here. But we must ensure the predictive validity. A good selection test paper should predict the future performances of the candidates.

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   Placement tests
   

Placement tests provide us with information which will help us to place the students at the stage of the teaching programme which suits them most to their current abilities. Our English Language Teaching programmes will cater to different proficiency levels of students: advanced, intermediate and elementary. If we place a student who has good command of English language in an elementary level course, the student may not be motivated to learn since the work in this class is not challenging.
Since our purpose is to place the student at a point of proficiency level, the test paper should compare the performances of candidates with one another. These tests are, therefore, Norm-reference. The test paper should discriminate the candidates adequately. For this purpose, test items of a wide range of difficulty level are included: if all test items are very easy, it is likely that most of the students do the test well and as such, it will not discriminate the candidates.
Placement tests are not based on a particular syllabus. Therefore, content validity is not of much relevance to these tests. However, a test specification can be drawn after we identify what skills the candidates should be able to perform during the course of study. For instance, in a course which requires candidates to perform orally should include some test items to test speaking skill of the candidates in the placement test. It is for this purpose that we recommend to construct placement test papers separately in each testing situation. A placement test paper administered in the English course of the University of Colombo may not be suitable for a course in some other institution.
A good placement test should predict the future performances of the candidates. If a candidate cannot cope up with the level of the course to which he gained admission, it is likely that the placement test has not worked well.

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