the construction and norm-finding of a rating scale for diagnosing attention deficit hyperactivity disorder in children

objective: evaluation and diagnosis are determinants of treatment outcome; therefore, diagnostic tools should be accurate. the purpose of the present research is construction and norm-finding of a rating scale for the diagnosis of attention deficit hyperactivity disorder (adhd). method: a checklist based on behavioral symptoms of adhd from clinical sources was constructed, based on interview with patients and the medical records. after being studied by specialists, this checklist was reduced to items and arranged in a rating scale format. the study population included tehran's elementary school students (boys and girls) from which a sample of 800 children was chosen in a random-cluster manner. then teachers were asked to rate the students according to the scale characteristics. after two weeks, the subjects were tested and interviewed using a corrected form of the scale, the rating scale of swanson, nolan and pelham (snap-iv) and diagnostic and statistical manual of mental disorders (dsm-iv). after data analysis the scale was reduced to 23 items. results: according to the results of the analysis, the scale had two factors: the first factor was hyperactivity that explained 37.41%, and the second factor was attention deficit that explained 33.78% of the total variance . cronbach's alpha was 0.96 and the alpha of the two subscales, hyperactivity and attention deficit, was 0.94 and 0.96, respectively. spearman-brown coefficient was 0.78 and scale coefficient correlation with a similar from (snap-iv) was 0.82. criterion validity coefficient of the scale was 0.76 and the content validity of the scale was confirmed by the experts. according to sensitivity analysis of the trait, the cutoff point of the scale was 35. considering the above findings, we can safely use the above scale in clinical studies. conclusion: considering the obtained values in the psychometric indexes and the consensus among specialists on the basis of test content validity and also considering the calculation methods of the cutoff point, we can safely use this scale in different clinical situations, epidemiological studies, and other researches and also for studying adhd children especially when teachers deal with evaluation of children behavior.