39. Which of the situations would increase the reliability of a language test?
(A) Having more items on the test
(B) Rating the test subjectively
(C) Designing a more difficult test
(D) Having variations in test task characteristics

What is reliability? 信度

An assessment is reliable if it measures the same thing consistently and reproducibly.

How can you increase the reliability of your assessments?

1. Use enough questions to assess competence.  (A)
2. Have a consistent environment for participants. 
3. Ensure participants are familiar with the assessment user interface.
4. If using human raters, train them well.
5. Measure reliability. 
6. Conduct regular item analysis to weed out ambiguous or poor performing questions. 

https://www.questionmark.com/six-tips-to-increase-reliability-in-competence-tests-and-exams/

增加信度的方法

1. 增加題數
2. 間隔時間適中
3. 難度適中
4. 受試者變異程度大(異質性高)
5. 評分客觀

https://yamol.tw/tfulltext-%E6%8F%90%E9%AB%98%E4%BF%A1%E5%BA%A6.htm

為了提高信度可以增加試題（例如從50題增加為100題）