We provide additional details about our data collection process, including the image prompts shown to authors (Figure \ref{fig:all-prompts}) and the writing setups (Figure \ref{fig:writing-setups}).

\begin{figure*}[t]
\centering
\begin{tabular}{@{}r@{\hspace{.2em}}l@{\hspace{.2em}}p{1.6\columnwidth}@{}}
(a) & Dog &\begin{subfigure}{1\textwidth}\includegraphics[width=.75\textwidth]{img/dog.pdf}\label{fig:dog}\end{subfigure}\\
(b) & Jail &\begin{subfigure}{1\textwidth}\includegraphics[width=.75\textwidth]{img/jail.pdf}\label{fig:jail}\end{subfigure}\\
\newline
(c) & Snow &\begin{subfigure}{1\textwidth}\includegraphics[width=.75\textwidth]{img/snow.pdf}\label{fig:snow}\end{subfigure}\\
(d) & Park &\begin{subfigure}{1\textwidth}\includegraphics[width=.75\textwidth]{img/park.pdf}\label{fig:park}\end{subfigure}\\
(e) & Marathon &\begin{subfigure}{1\textwidth}\includegraphics[width=.75\textwidth]{img/marathon.pdf}\label{fig:marathon}\end{subfigure}\\

\end{tabular}
\caption{Prompts used in the story writing stage of our data collection.}
\label{fig:all-prompts}
\end{figure*}

\subsection{Motivating LabintheWild authors}\label{sup:litw-motivator}
Since LabintheWild is a volunteer-based crowdsourcing platform, we design our task such that participants can learn about their personality through story writing as a motivation. The study was advertised on the front page of LabintheWild and posted on social media to recruit participants.
% Following best practices \cite{august2018framing}, the study was advertised on the front page of LabintheWild and posted on social media to recruit participants.

Once a participant finishes their story, we compute their personality estimate (using the Five Factor Model) based on their story language.
Specifically, we extract their pronoun usage using the pronoun categories in LIWC \cite{liwc2015}, and predict personality scores using the coefficients from \citet{schwartz2013personality}.
At the end of the task, we display their personality predictions along with short descriptions of which trait is the most present in their writing (i.e., the trait whose score has the highest magnitude).

Optionally, participants could take a short personality questionnaire \cite [TIPI;][]{gosling2003very} before seeing their writing-based personality results.
Those who answered these questions could then see their questionnaire-based and their writing-based personality estimates at the end of the task. The end of the task also debriefs participants, explaining the goal of the study and researcher contact information.


% \ms{Remove everything that is already said in the main body of the paper (once we 100\% settle on that.}
% \ms{Also add details about the pronoun-based predictor that motivates authors.}

 \begin{figure*}[t]
    \centering
    \begin{subfigure}[]{1\columnwidth}
        \centering
        \includegraphics[width=1.05\columnwidth]{img/all_interface.png}
        \caption{}
        \label{fig:all_interface}
    \end{subfigure}%
    ~ 
    \begin{subfigure}[]{1\columnwidth}
        \centering
        \includegraphics[width=.65\columnwidth]{img/accordion_interface.png}
        \caption{}
        \label{fig:accordion_interface}
     \end{subfigure}%
    \caption{\label{fig:writing-setups}Writing interfaces for the crowdsourcing study using the jail cartoon. (a) is all-at-once interface and (b) is the accordion interface. For (b), participants could see all images at the top, but had to write 1-2 sentences about each image separately though an accordian of text boxes. 
    }
\end{figure*}

