en عمومى General كاربردي Applicable <span style="font-size:11pt"><span style="line-height:normal"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">The nonparametric estimation(NE) of kernel polynomial regression (KPR) model is a powerful tool to visually depict the effect of covariates on response variable, when there exist unstructured and heterogeneous data. In this paper we introduce KPR model that is the mixture of nonparametric regression models with bootstrap algorithm, which is considered in a heterogeneous and unstructured framework. Also, the optimal properties of estimators have been considered. Finallly, we have studied a real heterogeneous and unstructured data using the KPR model.</span></span></span></span></span> COVID-19, nonparametric estimation, Kernel polynomial regression model, pridiction analysis, graphical model. 135 156 http://jsri.srtc.ac.ir/browse.php?a_code=A-10-115-2&slc_lang=en&sid=1 Farzad Eskandari فرزاد اسکندری askandari@atu.ac.ir 10031947532846002397 10031947532846002397 Yes Allameh Tabataba'i University Sima Naghizade Ardebili سیما نقی‌زاده اردبیلی naghizadeh@sanjesh.org 10031947532846002398 10031947532846002398 No National Organization for Education Testing سازمان سنجش آموزش کشور Dana Naderi دانا نادری naderidana@yahoo.com 10031947532846002399 10031947532846002399 No Allameh Tabataba'i University Mohammad Mahdavi محمد مهدوی sina47606@gmail.com 10031947532846002400 10031947532846002400 No Allameh Tabataba'i University Ali Fakhrae علی فخرایی a.fkh9095@gmail.com 10031947532846002401 10031947532846002401 No Allameh Tabataba'i University