# The Impact of Technical Error of Measurement on Somatotype Categorization
## 4 Discussion  
The results of this study demonstrate that TEM should be taken into account when calculating somatotype category. A lower TEM reduces the chance of mis-categorizing a person with respect to their somatotype, and increases the reliability of determining the dominant somatotype in a simplified categorization. This is an important finding in the context of research or applied practice that groups participants according to somatotype. This study demonstrated that nearly one third (29.4%) of the results from an individual with a high technical skill (ISAK Level 3) misclassify somatotype categories. Therefore, researchers should be aiming for TEMs < 2.5% for skinfolds and <0.5% for all other measures in line with those demonstrated in the current study. Somatotype papers that utilize ISAK protocols often report individual measure TEMs of a similar magnitude to those shown in the current data set [33; 34; 35]. When TEM is at ISAK Level 1 accreditation threshold, there is a larger spread of values on the somatchart compared to those of a higher technical competency. The reliability of somatotype also demonstrates that mis-categorization occurs more often with higher TEMs and with a detailed approach to classification. There are very few somatotype-focused papers that report TEM as standard [24; 25; 26; 27; 28; 29; 30], and there are no other known papers that look specifically at how error can affect somatotype categorization. Previous researchers have attempted to establish population somatotype trends in specific sports. [PERSON] et al. [14] compared the Judo athletes in their study to untrained students indicating that judoist were more mesomorphic and ectomorphic than untrained participants (Table 2). However, despite using simplified categorization the paper demonstrated no consideration of TEM when categorizing the participants potentially leading to up to 6 of their judoists being classified incorrectly in terms of their somatotype group. The influence of TEM on the categorization of the judoists, in particular, could be important as this group had the most population variability due to the presence of athletes from \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Somatotype Category** & **RTEM** & **L23 TEM** & **L1 TEM** \\ \hline Detailed & 39.7\% & 61.8\% & 72.1\% \\ Simplified & 29.4\% & 35.3\% & 38.2\% \\ \hline \hline \end{tabular} Note: RTEM = Researcher TEM, L23 TEM = Error associated with ISAK Level 2 and 3 TEM, LITEM = Error associated with ISAK Level 1 TEM.  
\end{table} 
Table 1: Percentage of participants potentially mis-classified based on 95% CI’s. Figure 1: Somatocharts demonstrating: (**a**) distribution of somatotype for study participants (n = 68); (**b**) mean somatotype for population with RTEM mean ranges; (**c**) Mean somatotype for population with L23 TEM mean ranges; (**d**) Mean somatotype for population with L1 TEM mean ranges. \(\bullet\) = population mean. **O** = RTEM 95% confidence intervals. different weight categories and there only being 15 participants in total. The variation due to weight-category was also present within a more recent paper investigating male and female judokas [15], and may account for some of the differences in somatotype groupings between the two papers. [PERSON] et al. [14] indicated their judo athletes to be mesomorphic and ectomorphic, whilst [PERSON] et al. [15] had more of a predominance towards mesomorphic and endomorphic. If TEM was taken into account in a similar manner to the current study in either paper, it may be that the two judo populations are more similar than they appear in terms of somatotype. Table 2 gives a summary of reviewed somatotype literature, indicating the impact of lack of acknowledgement of TEM on potential categorization. Certain sports indicate that their athletes' somatotype is often determined by the task requirements of particular positions [18; 20], age [17] or competition standards [18]. Detailed categorization is often used to determine these differences between position, age or competition standard.