en تخصصي Special پژوهشي Research <span style="font-size:11pt"><span style="text-justify:inter-ideograph"><span style="line-height:normal"><span calibri="" style="font-family:"><b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""><span style="color:black">Objective:</span></span></span></b><b> </b><span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">This review aims to address the critical role of sample size calculation in designing and conducting animal studies related to diabetes and obesity, particularly focusing on experimental comparison methods like ANOVA design.</span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="text-justify:inter-ideograph"><span style="line-height:normal"><span calibri="" style="font-family:"><b><span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">Materials and Methods</span></span></b><b><span dir="RTL" lang="FA" style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">:</span></span></b> <span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">We discuss the factors influencing sample size decisions, including type I and type II errors, effect size, and standard deviation. We emphasize the importance of avoiding common pitfalls, such as using rules of thumb or arbitrary choices, and advocate for utilizing established formulas to ensure accurate and reliable sample size determination.</span></span><i><span dir="RTL" style="font-size:10.5pt"><span style="font-family:"Times New Roman","serif""></span></span></i></span></span></span></span><br> <span style="font-size:11pt"><span style="text-justify:inter-ideograph"><span style="line-height:normal"><span calibri="" style="font-family:"><b><span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">Results</span></span></b><b><span dir="RTL" lang="FA" style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">:</span></span></b> <span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">This review presents relevant equations for calculating sample size in animal studies with an ANOVA design, providing researchers with a framework for determining the appropriate number of animals needed to achieve robust and ethical research.</span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="text-justify:inter-ideograph"><span style="line-height:normal"><span calibri="" style="font-family:"><b><span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">Conclusion</span></span></b><b><span dir="RTL" lang="FA" style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">:</span></span></b> <span style="font-size:10.5pt"><span new="" roman="" style="font-family:" times="">Accurate sample size calculation is essential for achieving powerful and statistically sound animal studies in diabetes and obesity research. Utilizing established formulas and avoiding arbitrary choices ensures reliable and ethical research practices while minimizing resource waste and maximizing the validity of collected data.</span></span></span></span></span></span><br> &nbsp; Sample size calculation, Clinical trials, Animal studies, Resource Equation Method, Randomized Controlled Trials Method 42 50 http://ijdo.ssu.ac.ir/browse.php?a_code=A-10-30-405&slc_lang=en&sid=1 Alireza Pakgohar 0000-0003-2512-1581 Yes Departmment of Statistics, Payame Noor University (PNU). Tehran, Iran. Hossein Mehrannia 0000-0001-9209-9519 No Department of Statistics, Behbahan Branch, Islamic Azad University, Behbahan, Iran.