# An Investigation of the Selection of LEED Version 4 Credits for Sustainable Building Projects
## 5 Discussion  
### Setting a LEED Certification Target and Points  
There is a note that most project point totals tend to cluster in groups just above the threshold of the target levels for both LEED 2009 and LEED v4. For example, LEED Silver projects generally achieve a total of around 52 points, just 2 points above the threshold for the Silver level. It seems likely \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multicolumn{3}{c}{**Rules**} & \multirow{2}{*}{**Support**} & \multirow{2}{*}{**Confidence**} \\ \cline{2-3} \cline{5-8}  & & & & & **Ins/rhs** & & **\#s/lhs** \\ \hline
1 & MRc5 & \(\leftrightarrow\) & INc2 & 0.901 & 0.98 \\
2 & IEQc3 & \(\leftrightarrow\) & INc2 & 0.883 & 0.98 \\
3 & IEQc3 & \(\leftrightarrow\) & WEc2 & 0.878 & 0.975 \\
4 & EAc1 & \(\leftrightarrow\) & WEc1 & 0.806 & 0.994 \\
5 & LTc2 & \(\leftrightarrow\) & INc2 & 0.86 & 0.99 \\
6 & IEQc3 & \(\leftrightarrow\) & INc1 & 0.869 & 0.965 \\
7 & IEQc3 & \(\leftrightarrow\) & MRc5 & 0.847 & 0.94 \\
8 & LTc2 & \(\leftrightarrow\) & INc1 & 0.838 & 0.964 \\ \hline \hline \end{tabular}  
* \(\leftrightarrow\): LEED credits with 2-way association. ** The lhs (left-hand side) and rhs (right-hand side) of the rule.  
\end{table} 
Table 4: The results of the association rule mining. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**ID**} & **Sig.** & **Cliff’s** & **Effect** & \multirow{2}{*}{**NFSAs**} & **ID** & **Sig.** & **Cliff’s** & **Effect** & \multirow{2}{*}{**NFSAs**} \\  & **WMW** & **Delta** & & & & & **WMW** & **Delta** & **Size** & \\ \hline \hline \multicolumn{8}{c}{**a. LEED**-Certified and LEED **Silver (n = 50)**} \\ INc1 & 0 & \(-\)0.379 & Medium & Positive & SSc3 & 0.017 & \(-\)0.19 & Small & Positive \\ LTc4 & 0.004 & \(-\)0.3 & Small & Positive & SSc4 & 0.013 & \(-\)0.185 & Small & Positive \\ EAc3 & 0.018 & \(-\)0.252 & Small & Positive & IEQc3 & 0.004 & \(-\)0.179 & Small & Positive \\ IEQc1 & 0.049 & \(-\)0.247 & Small & Positive & SSc1 & 0.027 & \(-\)0.173 & Small & Positive \\ IPc1 & 0.015 & \(-\)0.191 & Small & Positive & IPc1 & 0.015 & \(-\)0.191 & Small & Positive \\ \hline \hline \multicolumn{8}{c}{**b. LEED Silver and LEED Gold (n = 67)**} \\ LTc4 & 0 & \(-\)0.415 & Medium & Positive & EAc5 & 0.002 & \(-\)0.212 & Small & Positive \\ LTc5 & 0 & \(-\)0.369 & Medium & Positive & Mrc1 & 0.018 & \(-\)0.2 & Small & Positive \\ LTc8 & 0 & \(-\)0.281 & Small & Positive & INc1 & 0.009 & \(-\)0.194 & Small & Positive \\ LTc6 & 0.004 & \(-\)0.247 & Small & Positive & LTc7 & 0.029 & \(-\)0.183 & Small & Positive \\ WEc3 & 0.001 & \(-\)0.244 & Small & Positive & LTc3 & 0.023 & \(-\)0.182 & Small & Positive \\ EAc1 & 0.026 & \(-\)0.234 & Small & Positive & EAc2 & 0.03 & \(-\)0.178 & Small & Positive \\ WEc2 & 0.022 & \(-\)0.224 & Small & Positive & SSc3 & 0.024 & \(-\)0.16 & Small & Positive \\ \hline \hline \multicolumn{8}{c}{**c. LEED Gold and LEED Platinum (n = 24)**} \\ EAc2 & 0 & \(-\)0.591 & Large & Positive & EAc1 & 0.009 & \(-\)0.351 & Medium & Positive \\ Mrc1 & 0.003 & \(-\)0.442 & Medium & Positive & EAc5 & 0.002 & \(-\)0.348 & Medium & Positive \\ Mrc3 & 0.002 & \(-\)0.438 & Medium & Positive & SSc6 & 0.03 & \(-\)0.283 & Small & Positive \\ IEQc6 & 0.001 & \(-\)0.433 & Medium & Positive & INc1 & 0 & \(-\)0.279 & Small & Positive \\ SSc4 & 0.001 & \(-\)0.424 & Medium & Positive & EAc3 & 0.004 & \(-\)0.248 & Small & Positive \\ IEQc5 & 0.004 & \(-\)0.404 & Medium & Positive & WEc1 & 0.016 & \(-\)0.246 & Small & Positive \\ EAc7 & 0 & \(-\)0.377 & Medium & Positive & WEc2 & 0.005 & \(-\)0.232 & Small & Positive \\ \hline \hline \end{tabular}  
* \(\leftrightarrow\): LEED credits with 2-way association. ** The lhs (left-hand side) and rhs (right-hand side) of the rule.  
\end{table} 
Table 3: The results of the Wilcoxon–Mann–Whitney (WMW) test and [PERSON]’s delta indexes between adjacent pairs of Leadership in Energy and Environmental Design (LEED) certificate levels.