papers/zoo-citizen-science/sections/08-evaluation.tex

\section{Evaluation}

\label{sec:evaluation}
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\subsection{Platform Statistics}

ZooPlatform operated for 14 months (December 2024--January 2026).

\begin{table}[H]
\centering
\caption{ZooPlatform operational statistics.}
\label{tab:stats}
\begin{tabular}{lc}
\toprule
\textbf{Metric} & \textbf{Value} \\
\midrule
Registered contributors & 23{,}847 \\
Active contributors (monthly) & 8{,}412 \\
Countries & 41 \\
Total observations & 4{,}217{,}394 \\
Species documented & 12{,}394 \\
Research-grade observations & 2{,}585{,}263 (61.3\%) \\
Survey-mode observations & 873{,}421 (20.7\%) \\
Challenges completed & 1{,}247{,}832 \\
Challenge completion rate & 43.2\% \\
Mean observations per active user/month & 35.7 \\
30-day retention rate & 67.4\% \\
\bottomrule
\end{tabular}
\end{table}

\subsection{Engagement Analysis}

\begin{table}[H]
\centering
\caption{Contributor engagement comparison with existing platforms.}
\label{tab:engagement}
\begin{tabular}{lccc}
\toprule
\textbf{Metric} & \textbf{ZooPlatform} & \textbf{iNaturalist} &
  \textbf{eBird} \\
\midrule
30-day retention & 67.4\% & 41.2\% & 52.8\% \\
90-day retention & 48.3\% & 23.7\% & 38.1\% \\
Obs./active user/month & 35.7 & 12.4 & 28.6 \\
Survey-mode usage & 20.7\% & N/A & 34.2\% \\
\bottomrule
\end{tabular}
\end{table}

ZooPlatform achieves 67.4\% 30-day retention, significantly higher
than iNaturalist (41.2\%) and eBird (52.8\%). Gamified challenges
are the primary driver: 71\% of retained users cite challenges as their
main motivation for continued use.

\subsection{Data Quality Validation}

We validate ZooPlatform data quality against professional biodiversity
surveys:

\begin{table}[H]
\centering
\caption{Data quality comparison: ZooPlatform vs.\ professional surveys
at 15 co-located sites.}
\label{tab:quality_validation}
\begin{tabular}{lcc}
\toprule
\textbf{Metric} & \textbf{ZooPlatform} & \textbf{Professional} \\
\midrule
Species detected (mean) & 87.3\% & 100\% (reference) \\
False positive rate & 3.9\% & 1.2\% \\
Abundance correlation ($r$) & 0.84 & --- \\
Phenology timing ($\pm$ days) & 3.2 & 1.8 \\
Cost per observation & \$0.12 & \$8.40 \\
\bottomrule
\end{tabular}
\end{table}

ZooPlatform detects 87.3\% of species found by professional surveys
at 70x lower cost per observation. The false positive rate of 3.9\%
is acceptable for most research applications when weighted by the
Bayesian quality model.

\subsection{Scientific Output}

ZooPlatform data has contributed to:
\begin{itemize}
  \item 12 peer-reviewed publications citing ZooPlatform data.
  \item 3 new species range extensions documented by citizen scientists.
  \item 7 conservation assessments using ZooPlatform occurrence data.
  \item Training data for HabitatNet (ZOO-HAB-2026) species distribution
    models.
  \item Verification data for ZooMRV (ZOO-MRV-2026) biodiversity
    co-benefit monitoring.
\end{itemize}


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