Usability, Reliability, & Validity and their types

1. EDUCATIONAL
ASSESSMENT
Qualities of a Good Test
Hina Jalal (Ph.D.) @AksEAina

2. Qualities of good
test
Usability
Reliability
Validity
Hina Jalal (Ph.D.) @AksEAina

3. What is Usability?
Usability is the method or process we use to determine how easy something is to
identify, comprehend, and ultimately use. We measure or rate usability by considering
five major attributes, or factors. They are as follows:
•Learnability - describes how quickly something can be understood and put to use.
•Efficiency - describes how quickly something can be used once understanding is
achieved.
•Memorability - describes how easily something can be put down, then picked up and
used after some time has passed.
•Errors - describes how often errors are created during use, and how quickly the user
can recover from them.
•Satisfaction - describes how pleasing something is to use.
Hina Jalal (Ph.D.) @AksEAina

4. Reliability refers to how dependably or consistently a test measures a characteristic.
If a person takes the test again, will he or she get a similar test score, or a much
different score? A test that yields similar scores for a person who repeats the test is
said to measure a characteristic reliably.
Reliability tells you how consistently a method measures something. When you apply
the same method to the same sample under the same conditions, you should get the
same results. If not, the method of measurement may be unreliable.
Reliability
Hina Jalal (Ph.D.) @AksEAina

5. Types of
Reliability
Hina Jalal (Ph.D.) @AksEAina

6. Validity tells you how accurately a method measures something. If a method measures
what it claims to measure, and the results closely correspond to real-world values, then it
can be considered valid. There are four main types of validity:
•Construct validity: Does the test measure the concept that it’s intended to measure?
•Content validity: Is the test fully representative of what it aims to measure?
•Face validity: Does the content of the test appear to be suitable to its aims?
•Criterion validity: Do the results correspond to a different test of the same thing?
Validity
Hina Jalal (Ph.D.) @AksEAina

7. Hina Jalal (Ph.D.) @AksEAina

8. Hina Jalal (Ph.D.) @AksEAina

9. Hina Jalal (Ph.D.) @AksEAina

10. Hina Jalal (Ph.D.) @AksEAina