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Engineering Science in
            Additive Manufacturing                                                       Experimental statistics in AM




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            Figure 8. The variety of the statistical and experimental practices used, as well as the level of sophistication across papers pertaining to orthopedic
            engineering and PBF. (A) The total proportion of papers using various experimental designs per year in each field. (B) The total proportion of papers using
            various statistical methods per year in each field. (C) The proportion of papers using at least one standardized experimental practice for each field. Image
            created by the authors.
            Abbreviations: ANOVA: Analysis of variance; OFAT: One factor at a time; PBF: Powder bed fusion.


            Table 4. Features used in experimental designs and statistical analyses of the highest‑quality sampled papers

            Manuscript                Experimental design recommendations          Statistical recommendations
                           Sample size   Randomization  Blocking  Standard   Design   Statistical   Model   Model   Plot
                           justification                   design  matrix given  test  selection  adequacy  results
            Vilanova et al. 41                                                                    
            Zhang et al. 18                                                                          
            Pfaff et al.  42                                                                        
            Flores Ituarte et al. 43                                                                  
            Tyagi et al. 44                                                                          
            Note: Each of the papers, except for Flores Ituarte et al.,  adopted a response surface methodology design, which used a full factorial design [Table 1].
                                               43
              Pfaff  et al.  designed a general method of finding   8 show examples of how to demonstrate experimental
                       42
            the process parameters necessary to maximize print   designs and visually show response surfaces.
            quality.  They  pointed  out  the  benefits  of  using  a  CCD,   The paper by Flores Ituarte et al.  is perhaps the most
                                                                                            43
            fitting a second-order model, made suggestions for the   straightforward paper yet: it focuses on only identifying
            most important predictor variables for PBF-LB/M while   the process parameters that influence the quality of
            showing the importance of setting parameter ranges, and   prints (tensile strength, porosity, etc.). They performed
            also discussed the advantages of aspects of DOE such as   a screening experiment but used a full factorial design,
            randomization and using contour plots to find operating   which is inefficient. However, without reporting the design
            conditions. They also covered some topics that we do not   matrix, it is not entirely clear what exact type of design was
            include in this paper, such as calibrating empirical results   used, or if they randomized the run order. They used an
            to an underlying theoretical model.  Figures  1, 2, 7, and   ANOVA to determine the significance of factor effects and


            Volume 1 Issue 4 (2025)                         11                         doi: 10.36922/ESAM025340021
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