\begin{longtable}{llrl}
\caption{Research gaps: characteristics with fewer than ten extracted studies}\label{tab:gaps}\\
\toprule
Group & Characteristic & studies & evidence status \\
\midrule
\endfirsthead
\multicolumn{4}{l}{\textit{(continued)}}\\
\toprule
Group & Characteristic & studies & evidence status \\
\midrule
\endhead
\bottomrule
\endfoot
B. Interior & Kitchen quality & 9 & pooled \\
B. Interior & Bathroom quality & 3 & descriptive only \\
B. Interior & Appliances & 1 & descriptive only \\
B. Interior & Flooring & 4 & descriptive only \\
B. Interior & Insulation & 3 & descriptive only \\
B. Interior & Storage & 9 & pooled \\
B. Interior & Luxury finishes & 3 & descriptive only \\
B. Interior & Smart-home systems & 0 & no study \\
C. Exterior & Landscaping & 5 & descriptive only \\
C. Exterior & Outdoor kitchen & 0 & no study \\
C. Exterior & Private recreation & 6 & descriptive only \\
D. Location & Walkability & 3 & descriptive only \\
D. Location & Distance to airport & 6 & descriptive only \\
E. Environment & Wildfire risk & 1 & descriptive only \\
E. Environment & Water quality & 6 & descriptive only \\
E. Environment & Urban heat & 2 & descriptive only \\
F. Neighbourhood & Unemployment & 6 & descriptive only \\
F. Neighbourhood & Vacancy & 4 & descriptive only \\
G. Market & Time on market & 2 & descriptive only \\
G. Market & Market liquidity & 3 & descriptive only \\
G. Market & Foreclosure status & 1 & descriptive only \\
G. Market & Distressed sale & 1 & descriptive only \\
G. Market & Seller urgency & 0 & no study \\
G. Market & Mortgage conditions & 0 & no study \\
H. AI-derived & Text sentiment & 0 & no study \\
H. AI-derived & Renovation descriptions & 0 & no study \\
H. AI-derived & Architectural style & 2 & descriptive only \\
H. AI-derived & Luxury language & 0 & no study \\
H. AI-derived & Urgency language & 0 & no study \\
H. AI-derived & Image-based condition & 1 & descriptive only \\
H. AI-derived & Visual quality & 1 & descriptive only \\
H. AI-derived & Interior design & 0 & no study \\
H. AI-derived & Multimodal embeddings & 3 & descriptive only \\
\end{longtable}