# A Study on Ergonomic Layout of Automotive Electronic Shift Buttons
## 4 Discussion  
To achieve ergonomic electronic shift button layouts and global standardization of these layouts, the following two research questions were addressed in this study:  
1. What constitutes an ergonomic electronic shift button layout? (**Research question 1**). 2. How does the ergonomic performance of electronic shift button layouts vary depending on driving experience? (**Research question 2**). To answer these questions, 12 different button layouts were derived considering the currently commercialized shift button layouts and ergonomic design principles. A total of 21 respondents with different levels of driving experience were recruited and required to \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Principle**} & \multirow{2}{*}{\begin{tabular}{c} **Pair of Layouts** \\ **Compared** \\ \end{tabular} } & \multirow{2}{*}{**Accuracy**} & \multirow{2}{*}{**Convenience**} & \multirow{2}{*}{**Rapidity**} & \multirow{2}{*}{**Learnability**} & \multirow{2}{*}{**Intuitivelyeness**} & \multirow{2}{*}{**Safety**} & \multirow{2}{*}{**Preference**} \\ \hline \multirow{5}{*}{Compatibility} & L2-L1 & \(\boldsymbol{-1.30}\)* & \(\boldsymbol{-1.60}\)* & \(-1.20\) & \(\boldsymbol{-2.60}\)** & \(\boldsymbol{-2.30}\)** & \(\boldsymbol{-1.90}\)* & \(\boldsymbol{-1.70}\)* \\ \cline{2-9}  & L4-L3 & \(-1.10\) & \(-1.40\) & \(-0.80\) & \(-1.60\) & \(-1.40\) & \(0.90\) & \(\boldsymbol{-1.40}\)* \\ \cline{2-9}  & L10-L9 & \(-2.10\) & \(-1.80\)* & \(\boldsymbol{-1.80}\)* & \(\boldsymbol{-3.30}\)*** & \(\boldsymbol{-3.90}\)*** & \(\boldsymbol{-2.70}\)*** & \(\boldsymbol{-3.20}\)*** \\ \cline{2-9}  & L12-L11 & \(-0.50\) & \(-0.40\) & \(-1.00\) & \(-0.90\) & \(-0.70\) & \(-1.20\) & \(-0.50\) \\ \hline \multirow{5}{*}{\
\begin{tabular}{c} Functional similarity \\ \end{tabular} } & L3-L1 & \(-0.10\) & \(0.20\) & \(0.10\) & \(0.00\) & \(-0.50\) & \(-0.30\) & \(-0.20\) \\ \cline{2-9}  & L4-L2 & \(0.10\) & \(0.40\) & \(0.50\) & \(1.00\) & \(0.40\) & \(0.70\) & \(0.10\) \\ \cline{2-9}  & L3-L9 & \(-0.50\) & \(0.00\) & \(-0.20\) & \(-0.60\) & \(-1.10\) & \(-0.80\) & \(-0.70\) \\ \cline{2-9}  & L4-L10 & \(0.50\) & \(0.40\) & \(0.80\) & \(1.10\) & \(1.40\) & \(1.00\) & \(1.10\) \\ \hline \multirow{5}{*}{
\begin{tabular}{c} Stereotype \\ \end{tabular} } & L6-L5 & \(0.40\) & \(0.70\) & \(0.30\) & \(0.80\) & \(1.30\) & \(0.90\) & \(0.70\) \\ \cline{2-9}  & L8-L7 & \(-0.10\) & \(0.50\) & \(0.30\) & \(-0.10\) & \(0.50\) & \(-0.20\) & \(0.50\) \\ \cline{2-9}  & L9-L11 & \(1.10\) & \(1.60\) & \(1.00\) & \(1.90\) & \(2.20\) & \(0.80\) & \(2.00\) \\ \cline{2-9}  & L10-L12 & \(-0.50\) & \(0.20\) & \(0.20\) & \(-0.50\) & \(-1.00\) & \(-0.70\) & \(-0.70\) \\ \hline \hline \end{tabular}  
* \(p<0.05\), **\(p<0.01\), ***\(p<0.001\).  
\end{table} 
Table 9: Evaluation results for experienced driver group: mean differences between layouts to which ergonomic principles were applied and layouts to which they were not applied. evaluate each of the layouts using 7 ergonomic evaluation measures (accuracy, convenience, rapidity, learnability, intuitiveness, safety, and preference). Based on the evaluation results, four research activities were performed. 1. Excellent shift button layouts that received high marks from all respondents (regardless of driving experience) were identified (_Research activity 1-1_). 2. Principles that should be considered when designing shift button layouts were determined (_Research activity 1-2_). 3. Excellent shift button layouts that received high scores from each driving experience group (driving for \(\leq\)2 years or \(>\)2 years) were identified (_Research activity 2-1_). 4. Principles that should be considered when designing shift button layouts for each driving experience group were determined (_Research activity 2-2_). Regarding _Research activity 1-1_, for all seven measures, L1, L2, L3, L4, L6, and L9 showed scores higher than 4 (\"Neutral\") and higher mean scores than L5, L7, L10, L11, and L12, with statistical significance in some of the pairwise comparisons (Figure 1).