diff --git a/.gitignore b/.gitignore
index 5693947..9788db3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 # Solr installation
 solr/**/*
+**/.DS_Store
 
 # Collection data
 solr_config/data/**/*
diff --git a/report/report.pdf b/report/report.pdf
index e48a339..dc12275 100644
Binary files a/report/report.pdf and b/report/report.pdf differ
diff --git a/report/report.tex b/report/report.tex
index 40b76fc..e4dedaf 100644
--- a/report/report.tex
+++ b/report/report.tex
@@ -5,6 +5,8 @@
 \usepackage{parskip}
 \usepackage{minted}
 \usepackage[utf8]{inputenc}
+\usepackage{subcaption}
+\usepackage{graphicx}
 
 \setlength{\parindent}{0pt}
 
@@ -305,6 +307,48 @@ search are a 100 results limit and the use of \texttt{t\_*} fields to match
 documents (lines 25 and 23 -- remember the definition of the \texttt{text} field).
 
 \section{User interface}
+Figure \ref{fig:ui} illustrates the IR system's UI showing its features.
+
+\begin{figure}[H]
+  \begin{subfigure}{\textwidth}
+    \centering
+    \includegraphics[width=0.8\textwidth]{ui_start.png}
+    \caption{The UI, when opened, prompts to insert a query in the input field
+    and press Enter. Here the user typed ``Lugano''.}
+    \vspace{0.5cm}
+  \end{subfigure}
+  \begin{subfigure}{0.45\textwidth}
+    \centering
+    \includegraphics[width=\textwidth]{ui.png}
+    \caption{After the user inputs a query and presses Enter, resulting images are shown on the
+    right. Found clusters are shown on the left using FoamTree.}
+  \end{subfigure}
+  \hspace{0.1\textwidth}
+  \begin{subfigure}{0.45\textwidth}
+    \centering
+    \includegraphics[width=\textwidth]{ui_cl.png}
+    \caption{When a user clicks a cluster, results are filtered depending on the
+    cluster clicked. If the user clicks again on the cluster, filtering is
+    removed.}
+  \end{subfigure}
+  \caption{The UI and its various states.}
+  \label{fig:ui}
+\end{figure}
+
+The UI has been implemented using HTML5, vanilla CSS and vanilla JS, with the
+exception of the \textit{FoamTree} library from the Carrot2 project to handle
+displaying the clustering bar to the left of search results.
+
+Event handlers offered by \textit{FoamTree} allowed for the implementation of
+the results filtering feature when a clustering in filtered.
+
+This is a single page application, i.e. all updates to the UI happen without
+making the page refresh. This was achieved by using AJAX requests to interact
+with Solr.
+
+All UI files can be found under the \texttt{ui} directory in the repository root
+directory. In order to run the UI, a ``CORS Everywhere'' extension must be
+installed on the viewing browser. See the installation instructions for details.
 
 \section{User evaluation}
 \end{document}
diff --git a/report/ui.png b/report/ui.png
new file mode 100644
index 0000000..e4b4afe
Binary files /dev/null and b/report/ui.png differ
diff --git a/report/ui_cl.png b/report/ui_cl.png
new file mode 100644
index 0000000..4f43b29
Binary files /dev/null and b/report/ui_cl.png differ
diff --git a/report/ui_start.png b/report/ui_start.png
new file mode 100644
index 0000000..a0ffaf8
Binary files /dev/null and b/report/ui_start.png differ