1. RELIABILITY IN TESTING
Büşra Nur Durmaz

2. CONTENTS Definition The Reliability Coefficient
The Standard Error of Measurement and The True Score
Scorer Reliability
How to Make Tests more Reliable
Reliability and Validity
References

3. WHAT IS RELIABILITY?
Consistency

6. Reliable or Not???

7. The Reliability Coefficient
What is reliability coefficient?

8. The Reliability Coefficient
What does the reliability coeffiecient do?
compare the reliability of different tests
The ideal reliability coefficient is……. (have no negative values)
What is the relaibility coefficient for a good vocabulary, grammar and reading tests?
What about listening and speaking?
How do we come up with the value of the reliability coefficient?
Test-retest method
Alternate (equivalent) forms method
Internal consistency: split-half method

9. The Standard Error of Measurement & The Trues Score
How close the scores of the tests that we are comparing??? ( The true score)
How can we arrive at this values?
Standard Error of measurement (SEm): ‘’It’s how much measured test scores are spread around a “true” score.’’ It’s calculated based on the realiability coefficient.
The higher the SEm the lower the reliability.

10. Scorer Reliability
So far we considered the reliability without thinking about the scorer reliability.
The perfect reliability of objective tests cannot be obtained in the subjective ones.
For compositions the reliability is over 0.9

11. How to make tests more reliable
Include more items. (Spearman- Brown Formula)
They should be independent of each other.
Not too long...
Unambiguous items
Clear & explicit instructions
Well typed, legible tests
Uniform and non-distracting conditions of administration
Items should be as objective as possible
A detailed scoring key
Train scorers (esp. the scoring is subjective)
Agree acceptable responses and scores
Number the candidates
Multiple, indepedent scoring (at least two scorers)

12. Reliability and Validity

13. REFERENCES
Brown, J. D. (2005). Testing in Language Programs: A Comprehensive Guide to English Language Assessement. McGraw-Hill College.
Fraenkel, J. R., Wallen, N. E., & Hyun, H. H. (1993). How to design and evaluate research in education (Vol. 7). New York: McGraw-Hill.
Hughes, A. (2002). Reliability. In Testing for Language Teachers (Cambridge Language Teaching Library, pp ). Cambridge: Cambridge University Press. doi: /CBO
(On 13rd of March, 2018) Retrieved from: measurement/

14. THANK YOU!