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

Obtaining Two Sets of Scores for Measuring Reliability

To calculate reliability, two sets of scores are necessary. There are different ways through which two sets of scores could be achieved:

1. 
   Test-Retest Method
   

The same test is administered to the same group of students twice. This seems to be an ideal way to obtain two sets of scores. However, there are several disadvantages of this method. First, there can be practical problems in repeating the test. Second, students will not be motivated to have the same test the second time and their performances in the second sitting will not be equal to that of the first. Further, if there is a long gap between the two tests, learning can take place and the second test performances will be better. Or else, students may forget things in the second time!

2. 
   Alternative-Test Method
   

Instead of repeating the same test, in this method, a parallel test is conducted in the second sitting. This seems to be a solution to some of the issues raised in the previous method. But it is very difficult to construct a parallel test paper. Suppose you include a question – an essay – in the first paper to write about Sri Lanka. What is the topic given in the second essay? – to write about India?

3. 
   Multiple Marking Method
   

Two examiners mark the same test paper. This method is practiced in most of the Sri Lankan Universities.

4. 
   Split-half Method
   

This is a more practical way of obtaining two sets of scores. In this method, only one test is conducted only once. The marks for each question will be taken separately and then sum of marks of odd number questions will be taken as one set and those of even numbers as another. The following example illustrates this:

Question No.	1	2	3	4	5	6	7	8	9	10
Score	8	7	6	9	7	5	9	7	4	3

Marks obtained by one student in an Achievement Test
First set of scores (odd numbers): 8 + 6 + 7 + 9 + 4 = 34
Second set of scores (even numbers): 7 + 9 + 5 +7 + 3 = 31
If the test items are arranged in the order of difficulty, this is an economical way to obtain two sets of scores.

4.