بررسی تجربی عوامل مؤثر در مطلوبیت زیبایی‌شناسانۀ تناسبات گنبدهای معماری ایرانی- اسلامی

Domes and their proportions play an important role in the visual aesthetics of Islamic architecture. Despite the importance of this element of Iranian architec­ture, no significant studies have been conducted on its geometric proportions. Previous researches are mainly concerned with their history, drawing meth­ods, formal typology and structural-climatic charac­teristics. The first question of the study concerns the concinnity of the dome and the variables that can re­produce its form and formal proportions. The second question, which in fact constitutes the main research question, is: What is the relationship between the proportions of variables composing the geometric form of the dome and people’s aesthetic prefer­ences? And, to compound this question further, what is the approximate value of this relationship in nu­merical proportions? To answer these questions, the research was conducted in two stages. The primary stage involved evaluations to identify the variables that, through being changed, could help reproduce the greatest number of dome types. One the one hand, drawing data from previous studies did not suf­fice to achieve this goal. On the other hand, control­ling or limiting these variables was crucial for obtain­ing a numerical proportion between them. The se­cond stage involved a survey design which was ad­ministered in two phases: pre-test and main test. The main test was designed as a multiple-choice computer survey in which the respondents were asked to select the dome which they perceived as the most beautiful from among a set of four presented domes, with var­ied proportions of one dome category based on the findings. In choosing the domes for the survey, we took care to select the types of domes whose forms were more familiar to our Iranian sample of respond­ents. Three pre-questionnaires were also distributed to control the effects of such factors as mode of presentation, light and materials. We first studied and categorized the concept of proportion, the types of domes and effective variables in the reproduction of the outer form of the domes and, then, evaluated the aesthetic experience of the respondents through pre­senting manipulated visual stimuli of “shoulder” and “base” sections of the dome. The data were fed into IBM SPSS Statistics and modelled by MANOVA and repeated measure ANOVA. The participants included an available sample of 86 students (f=40, m=46; ma­joring in architecture=41, majoring in other fields=45) selected from among the students of all faculties at Tabriz Islamic Art University. The participants took part in our exclusive experiment designed and coded with OpenSesame, an open-source software product. The findings suggest the existence of a significant re­lationship between the aesthetic preferences of the respondents and the proportions composing the di­mensions of the domes, especially the ones with a “base” section (2±0.06). This study shows that the beauty of Iranian-Islamic domes is not a coincidence; but rather, it follows a certain set of aesthetic princi­ples and rules.