@article{article_1994635, title={The Effect of Replication Size and Estimator Choice on Dual Response Surface Optimization under Skewed and Contaminated Data}, journal={Erciyes Üniversitesi Fen Bilimleri Enstitüsü Fen Bilimleri Dergisi}, volume={42}, year={2026}, DOI={10.65520/erciyesfen.1994635}, url={https://izlik.org/JA45ZR39YL}, author={Kozan, Agah}, keywords={Sağlam parametre tasarımı, ikili yanıt yüzeyi metodolojisi, tekrar sayısı, ölçek tahmini, kirlenmiş veri}, abstract={Within-design-point replication and estimator choice are usually examined separately in dual response surface optimization. This study evaluated their joint influence under clean, skewed, and additively contaminated data using 39 scenarios, 200 Monte Carlo replications, and nested samples at r ∈ {3,5,8,10}. The primary analysis fixed a skewness-adjusted location estimator and compared six classical and robust scale estimators. Decision quality was assessed against full-process and baseline-process targets. Increasing r from 3 to 8 reduced mean full-process regret by 66.9% under clean data, 40.5% under skew-only data, and 38.7%, 24.6%, and 22.5% under low, moderate, and high contamination probabilities. In the joint location–scale analysis, the same transition improved full-process regret in 79 of 80 combinations and baseline-process regret in all 80. No estimator was uniformly best. Standard deviation performed best under clean data and often when contamination was treated as part of the operating process. Robust scale estimators performed better in some low- and moderate-contamination settings, especially when preserving the baseline process was the aim. The benefit of additional replication remained consistent across estimator choices, evaluation targets, alternative process geometries, mild response-surface misspecification, finite-sample calibration, and positivity treatments. A printing-process benchmark and a semi-synthetic extension showed the same qualitative pattern under clean and mild-disturbance conditions. Within the fixed 27-point design, replication had the most consistent effect, while the preferred estimator depended on the target and contamination structure. Together, the results provide practical guidance for planning replication and selecting estimators in dual response surface studies.}, number={3}