Background and Objective: Nowadays, by extension of research in medical and social sciences, education and managing most of outcomes measurers by cheklists,questionnaires, scales and educational tests or raters evaluations to quantify the human behaviors. Reliability and validity are the most important indexes in measurement to obtain true values. Enough knowledge and understanding the reliability and validity are important principle of methodology in study designing. Unfortunately, psychometric aspects of measures have not been applied in some situations and studies. The objective of current document is to show the concepts of reliability, validity, psychometric aspects and their types of measurements for researchers. 

Key words: Validity, Reliability, Psychometric , Cranach's Alpha, Kappa Coefficient, Factor Analysis

Funding: This study was funded by Qom University of Medical Sciences.

Ethical approval:The Ethics Committee of Qom University of Medical Sciences approved the study.

Conflict of interest: none declared.

How to cite this article. Mohammadbeigi A, Mohammadsalehi N, Aligol M. Validity and Reliability of the Instruments and Types of Measurment in Health Applied Researches. J RafsanjanUniv Med Sci 2015 13(10): 1153-70. [Farsi]