Reliability refers to the consistency or repeatability of measurement results. There are four types of reliability: inter-rater, parallel forms, test-retest, and internal consistency. Reliability can be estimated using external consistency procedures, which compare results from independent data collection processes, or internal consistency procedures, which assess consistency across items in the same test.

1. RELIABILITY

2. DEFINTION
• In research, the term reliability means
“repeatability” or “consistency”.
• Reliability refers to whether or not you get the
same answer by using an instrument to
measure something more than once.

3. RELIABILITY TYPES
There are four types of reliability that you can explore:
• Inter-rater reliability: In instances where there are multiple
scorers or 'raters' of a test, the degree to which the raters'
observations and scores are consistent with each other
• Parallel forms reliability: In instances where two different
types of a measurement exist, the degree to which the test
results on the two measures is consistent
• Test-retest reliability: The degree to which the
measurement's results are consistent over time
• Internal consistency: The degree to which every test item
measures the same construct

4. METHODS OF ESTIMATING RELIABILITY
• There are number of ways of estimating
reliability of an instrument.
• Various procedures can be classified into two
groups:
• External consistency procedures
• Internal consistency procedures

5. External Consistency Procedures
• External consistency procedures compare
findings from two independent process
of data collection with each other as a means
of verifying the reliability of the measure.

6. Internal consistency procedures
• This form of reliability is used to judge the
consistency of results across items on the
same test.

7. THANK YOU