# A Study on Ergonomic Layout of Automotive Electronic Shift Buttons
## 2 Methods
### Design Alternatives  
In an effort to properly address the research question of 'What constitutes an ergonomic electronic shift button layout?', this study aimed at generating many different layout design alternatives in an exploratory/opportunistic way, and then comprehensively/comparatively evaluating them in terms of the ergonomic performance.  
Note that in generating the button layout design alternatives, the current study considered only the four shift buttons (P, R, N, and D) pertaining to the key elements for the shifting operation, not other functional buttons for starting the engine or changing the driving modes (sport, comfort, eco, etc.); furthermore, other design factors besides layout, such as the size, color, material, or spacing of buttons, were not considered.  
The ergonomic principles applied to generate various button layout design alternatives were as follows:  
* _Consistency: Maintaining consistency of the component layout across the same or similar systems (systems designed for the same or similar functions)_[18; 19; 20]: The button layout was designed such that it is the same as or similar to commercialized button layouts that have been adopted for popular car brands, as shown in Table 1.
* _Functional similarity: Grouping components that are functionally related in the operation of the system_[9; 13; 21; 22]: The P and N buttons associated with the stop function were positioned close together and away from the D and R buttons associated with the driving function. [PERSON] et al. [4] stated that locating the push switch for shifting to hold the vehicle stationary (i.e., P) away from those used to change the driving force direction (i.e., D and R) could help prevent mis-shifts into the P position when changing the driving force direction.
* _Compatibility: Designing control layouts such that the system response (movement) to the user operation meets his/her expectations_[18; 20; 23]: Relative to the N button, the D button was positioned in front and the R button behind.
* _Stereotype: Designing control layouts in line with the expectations of a particular group of users_[13]: The D and R buttons that determine the direction of longitudinal vehicle control were positioned in the longitudinal direction. A total of 12 design alternatives were generated through the following two-step process.
* Step 1: A total of six button layouts were derived by applying the consistency principle, in other words, designed to be the same as or similar to internationally manufactured/commercialized ones. These six layouts were odd-numbered (hereafter referred to as L1, L3, L5, L7, L9, and L11).
* Step 2: Each of the six button layouts derived in Step 1 was slightly modified by applying other ergonomic layout design principles instead of the consistency principle,  
\begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Group**} & \multirow{2}{*}{**Experience Using Electronic Shift Buttons**} & \multirow{2}{*}{**N**} & \multicolumn{3}{c}{**Driving Experience (Years)**} \\  & & & **Mean** & **SD** & **Range** \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} Novice driver \\ (\(\leq\)2 years) \\ \end{tabular} } & No & 6 & 0.99 & 0.43 & 0.50–1.67 \\  & Yes & 5 & 5.96 & 0.51 & 0.42–2 \\  & Total & 11 & 1.05 & 0.48 & 0.42–2 \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Experienced \\ driver \\ (>2 years) \\ \end{tabular} } & No & 5 & 6.58 & 1.26 & 4.75–8 \\  & Yes & 5 & 5.58 & 0.51 & 4.67–6.08 \\ \cline{1-1}  & Total & 10 & 5.96 & 1.15 & 4.67–8 \\ \hline \end{tabular}
\end{table}
Table 2: Respondent characteristics.  
generating six other novel button layouts. These six layouts were even-numbered (hereafter referred to as L2, L4, L6, L8, L10, and L12).  
Table 3 summarizes/illustrates the 12 design alternatives with the 6 odd-numbered and 6 even-numbered layouts in the left and right columns, respectively; furthermore, the ergonomic layout design principles applied in each design alternative are also indicated.