Guruge, M. LEdirisinghe, P. M2022-01-032022-01-032021-09-252783-8862https://rda.sliit.lk/handle/123456789/436Refractive index is one of the physiochemical properties of substances which is mostly used in optical sciences and provides very important information about the behavior of ray of light in various materials. This study was conducted to identify highly associated compositions of building windows non float processed glasses with refractive index and to develop a linear model to represent such relationships. Results of this study will provide a clear indication on how rays of light behave when passing through building windows non float processed glasses according to its composition. For compositions of glass, it was considered elements contained in corresponding oxide other than oxide type. A multiple linear regression model fitted for the data found that only sodium (Na), aluminum (Al), silicon (Si) and calcium (Ca) are highly associated with refractive index of building windows non float processed glasses. There was a strong positive linear relationship between refractive index and calcium (Ca) while a moderately strong negative linear relationship between refractive index and silicon (Si) for building windows’ non float processed glasses. Both sodium (Si) and aluminum (Al) had weak negative linear relationships with refractive index.enMultiple Linear RegressionRefractive IndexArticle