According to Alvan Feinstein, the world of clinical medicine faces two challenges of mensuration and quantification. An individual-level challenge called mensuration and a group-level challenge called quantification. Feinstein calls mensuration the process of converting clinical observations (observed phenomena) into primary raw data, which are expressed as numbers and digits. Then, he called the conversion of raw data into digits and numbers specific to groups, such as the average, quantification. Quantification also has group indices to describe physical symptoms and clinical phenomena. In many scientific disciplines, the extension metry/metrics has been used to represent works based on measurement or mensuration. Combined terms with this suffix were first used by Sir F. Galton for biometry about a century ago to represent the combination of statistical committees with biological knowledge. Biometrics gradually expanded into the realm of biology, and three areas of anthropometry, sociometry, and psychometric emerged. In addition to biological activities, the scope of metrics has been widely extended to other sciences such as econometrics, technometrics, cliometric, bibliometrics, and chemometrics. Therefore, the idea and name of clinimetric is not new. The cousins of the large metrics family have been waiting for the word clinimetrics for a long time, and they may wonder why clinicians and therapists joined them so late. To express people's height, scale data in centimeters or inches, to express gender, scale data such as men and women, and to classify the severity of the disease, scales such as mild, moderate and severe or +1, +2, +3 and. . . . were defined. All the scales and criteria used in mensuration are to describe the types of treatments so that the observed phenomena can be divided into specific categories and analyzed. Quantification occurs after collecting primary raw data and assigning it to categories to make comparisons between them. In the categorized raw data, indicators can be calculated for each group. The average as an indicator of the health status of severely ill men receiving a treatment is one of them. In a complete and comprehensive definition, clinimetrics is an indicator of clinical phenomena. It evaluates or describes clinical and laboratory signs, symptoms, and findings using scales, indicators, and other quantitative instruments. Clinical measurement can be divided into two types of activities. One of them is mensuration in which raw data is collected to label or group so that the observed phenomena. Mensuration means what determines the status of each individual to generate such variables and raw data such as "place of birth: Mashhad", "gender: female", "age: 42" and "functional status: level 4". Another type of clinical trial can be called quantification that involves the collection of raw data in a group and summarizing the group’, s characteristics, and sometimes a comparison is made between two or more groups. In quantification, it can be said that in a special group of 57 people, 81% of them were born in Mashhad, 56% were women and their average age was 46. 2 years and their average functional status was level 3. Then we can compare this group with another group of people to achieve the conclusion for quantification. Over the years, the term "clinical epidemiology" has been used to quantify and compare clinical phenomena. Hence, clinimetrics is limited to mensuration activities to distinguish between these two types of measurements. On the other hand, clinical epidemiology can be a subset of clinimetrics or vice versa clinimetrics subset of clinical epidemiology. With these limitations, clinimetrics can be related to indicators, rating scales, and other conditions that are defined to describe or measure physical signs and symptoms or overt clinical phenomena in clinical medicine. Although markers, indicators, and measurements are components of clinimetrics, the main focus of this branch of science is expanding on methodology for measurement to have the necessary application. This issue is related to the quality of measuring instruments and now there is more focus on the development process of instruments than their final format. Dr. Feinstein, known as the father of clinical epidemiology, dreamed of a new field, which he introduced as clinimetrics in the early 1980s and scientists like Henrica De. Wet, Per Bech and Paul Krabbe pursued his work. He wrote a book on Clinimetrics after writing a book on Clinical Biostatistics and Clinical Epidemiology. He published four consecutive articles in the journal Ann. Intern Medicine (September to December 1983) to emphasize the necessity of basic sciences in medicine as "clinical medicine". In the last of these articles, he introduced the field of clinimetrics and predicted the types of opposition to the establishment of this field. The concept of clinimetrics gradually took its place in the medical literature. Given his scientific background in mathematics, statistics and psychometrics, he now teaches clinimetrics at the VU University of the Netherlands and has begun a wide range of activities to promote it (www. clinimetrics. nl/). He and his colleagues believe that clinimetry and psychometry are two sides of a coin. However, people like Per Bech in his book "Clinical Psychometry-2012" consider clinical psychometry to be the same as "clinimetrics" in psychiatry. Paul Krabbe of the University of Groningen in the Netherlands has dedicated chapter 13 of his book to measuring health and health status to clinimetrics. Clinimetrics has been proposed in other sciences such as physiotherapy and rehabilitation sciences by Dekker et al. (2005). Soon courses on clinimetrics will begin in faculties that deal with patients and clinical sciences (such as rehabilitation, dentistry and medicine). Perhaps the best place to start this field is in the "basic sciences" group at medical universities, so that Dr. Feinstein's dream of making the field of clinical studies as a basic field comes true. It is hoped that the pioneering universities of medical sciences in the country will also contribute to the development of this field by understanding the necessity of establishing such a field as a basic and complementary field.