Reliability and Validity of Objective Tests - Essay Example

The reliability of a subjective test is determined by the degree of its correctness and consistency in providing information regarding the examinee. A reliable test should yield identical results when run multiple times or when used with the same group of students because it is constant in its procedures and criteria. Reliable test results are stable and consistent (McMillan, 2008; Atherton, 2011).

Validity is the ability of a test to measure the intended objective. The three types of validity are content, criterion, and construct validity. Content validity is achieved if the content of the test matches the intended objectives. Criterion validity is determined by the capability of the test to relate to other external factors. Construct validity considers educational variables while predicting the test results (McMillan, 2008). An example of an objective test is:

1. Which one of the following statements best defines the term pollination
a) Transfer of pollen grains from the stamen to the stigma
b) Development of pollen grains
c) Transfer of pollen grains from stigma to stamen
d) Process by which insects visit flowers

The reliability of a subjective test can be measured by giving the same test more than once or giving creating two forms of the same test with slight variations. The reliability of the such test is measured by calculating the correlation of the consistency. Internal consistency is determined by correlating half of the assessment with the remaining half. Reliability consistency ranges from 0 to 1.0 with 0 representing the absence of reliability while 1 depicts perfect reliability. Tests with a reliability coefficient of above 0.8 are considered to be standard while those with a coefficient below 0.5 are considered to be less reliable. Validity is measured by establishing if the test meets or measures the intended objective (McMillan, 2008; Atherton, 2011).

Determining the reliability and validity of a test is important since it helps in establishing the accuracy of the grade obtained using such a test, if a test is valid and reliable the results obtained are considered a true depiction of the student's level of understanding

2. Differentiate between formative and summative assessment. You created a midterm exam for your class. Is this type of assessment formative or summative? Why?
Formative assessment is used by teachers or lecturers to obtain feedback from students regarding their degree of understanding or learning and is conducted throughout the learning process. On the other hand, summative assessment is conducted after a specified period, which is mainly at the end of a module, project, or after completion of a course (McMillan, 2008). Summative assessments comprise final project and midterm examinations.

An additional difference is that summative assessments are graded and used to establish if students have fulfilled certain preset outcomes while formative assessments are not graded. Another difference is that summative assessments are conducted after a specific learning period while formative assessments can be conducted even before starting the teaching to establish areas to emphasize or in the course of learning but the assessment time is not specific. A midterm test is summative since it is conducted at a specified period which is in the middle of the term (McMillan, 2008; Atherton, 2011). Read More