Have you prepared these very important questions from Unit 6 for IGNOU PGDCFT MSCCFT MCFT005 Exam? Don't miss this chance to score good marks - start!

Unit 6 Test Measurement

1. What are the different types of validity?

There are three types of validity: 

(i) content validity; 

(ii) criterion- related validity; 

(ii1) construct validity. 

2. Elaborate on the classification of tests according to the function. 

Classification of tests as per the function: 

i) Educational tests, 

ii) Personality test, and 

iii) Aptitude tests. 

3. What are the different scales used in research? 

i) Nominal scale is largely used to classify people or objects in certain categories. 

ii) In Ordinal scale the data 1s arranged in ascending or descending order. 

iii) Interval scale is also called equally appearing intervals scale. 

iv) Ratio scale is primarily used in physical measurement

4. Explain different types of reliability with help of examples. 

Reliability refers to the consistency of a research tool or measurement. It determines whether a tool produces stable and consistent results when used repeatedly under the same conditions. Several techniques assess reliability, including:

• Test-retest reliability: This method involves administering the same test to the same group of people on two different occasions. The correlation between the two sets of scores indicates the test's stability over time. For example, a researcher might administer an anxiety questionnaire to a group of students and then re-administer it a week later. A high correlation between the two sets of scores would suggest the questionnaire has good test-retest reliability.
• Alternate or parallel-forms reliability: This technique uses two equivalent forms of the test, administered to the same group with a time interval. The correlation between the scores on the two forms indicates the consistency of responses to different items measuring the same construct. For example, a researcher might create two versions of a maths test with different but equivalent questions and administer them to the same group of students. A high correlation would suggest good parallel-forms reliability.
• Split-half reliability: This method involves splitting a single test into two equivalent halves and correlating the scores on each half. This assesses the test's internal consistency, meaning the degree to which all items in the test measure the same construct. For example, a researcher could split a personality questionnaire into two halves and compare the scores on each half. A high correlation suggests good split-half reliability.
• Rational equivalence method: This method determines reliability by assessing the degree to which different forms of a test are interchangeable. It is frequently used to evaluate the reliability of psychological tests.

It is essential to remember that a valid test can be reliable, but a reliable test may not always be valid. Validity refers to whether a tool truly measures what it intends to measure.

5. How do you calculate the validity and reliability of a test?

A good research tool should be both valid and reliable. Validity means that the tool measures what it is supposed to measure. Reliability refers to the consistency of the tool, i.e. it should produce similar results under similar conditions.

• Validity: There are three main types of validity: content, criterion-related, and construct validity.
• Content validity examines whether the test items are relevant to the research objectives and cover a representative sample of the behaviour being measured. This is often determined by experts in the field.
• Criterion-related validity assesses the relationship between the test scores and an external criterion. This can be predictive validity (the ability of the test to predict future performance) or concurrent validity (the agreement between the test scores and scores on an established measure).
• Construct validity investigates whether the test accurately measures the specific psychological trait it is designed to measure.
• Reliability: Several methods can be used to assess reliability, including:
• Test-retest method: The same test is administered twice to the same group with a time interval. The correlation between the two sets of scores indicates the test's stability over time.
• Equivalent or parallel-forms method: Two equivalent forms of the test are administered to the same group. The correlation between the scores on the two forms shows the consistency of responses to different item sets.
• Split-half method: A single test is divided into two equal halves, and the scores on each half are correlated to assess internal consistency.
• Rational equivalence method: This method assesses the degree to which different forms of a test are interchangeable and is often used with psychological tests.

It's important to note that a valid test can be reliable, but a reliable test might not always be valid.