The document discusses the concept of reliability in measurement, emphasizing its importance in producing consistent results across repeated tests. It outlines various types of reliability, including internal consistency, test-retest, split-half, and inter-rater reliability, along with methods for evaluating them such as Cronbach's alpha. Ensuring reliability is crucial for accurate decision-making in both research and clinical contexts.

1. Presented By:
Ramsha Makhdum

2.  Reliability refers to the extent to which a scale produces consistent results, if the
measurements are repeated a number of times.
 Reliability is a measure of the stability or consistency of test scores.
 When a measurement procedure yields consistent scores when the phenomenon being
measured is not changing
 Degree to which scores are free of “Measurement Error Consistency of the
measurement
 Example: Weighing scale used multiple times in a day by the same individual.

3.  Internal consistency reliability
 Test-retest reliability
 Split–half method
 Inter-rater reliability

4.  Also known as inter-item reliability.
 It is the measure of how well the items on the test measure the same construct or
idea.

5.  Cronbach's Alpha are most commonly used used to measure inter-item reliability to see if
questionnaires with multiple questions are reliable. Value must by above 0.7.

6.  Test-retest reliability is a measure of reliability obtained by administering the same test
twice over a period of time to same group of individuals.
 Test-retest reliability is the degree to which scores are consistent over time.
 Same test- different times
 Example: Administering the same questionnaire at 2 different times such as IQ test.

7.  A method of determining the reliability of a test by dividing the whole test into two
halves and scoring the two halves separately.
 Especially appropriate when the test is very long.
 The most used method to split the test into two is using the odd-even strategy.

8.  Inter-rater reliability is the extent to which two or more raters (or observers,
coders, examiners) agree.
 Inter-rater reliability is essential when making decisions in research and clinical
settings.

9.  Neuman, L. (2014). Social Research Methods: Qualitative and Quantitative Approaches.
Pearson Education Limited.