diff --git a/src/classes/dataSource.h b/src/classes/dataSource.h
index 22a04a788f..c3117f5e25 100644
--- a/src/classes/dataSource.h
+++ b/src/classes/dataSource.h
@@ -59,6 +59,9 @@ template <typename DataType> class DataSource : public Serialisable<const CoreDa
     public:
     // Return data name
     std::string_view dataName() const { return dataName_; }
+    // Set Data Source Type
+    typename DataType::Formatter &externalDataSource() { return externalDataSource_; }
+
     // Return if data exists and has been initialised
     bool dataExists() const
     {
diff --git a/src/gui/keywordWidgets/CMakeLists.txt b/src/gui/keywordWidgets/CMakeLists.txt
index 6bfedafb88..ddaaf08b2d 100755
--- a/src/gui/keywordWidgets/CMakeLists.txt
+++ b/src/gui/keywordWidgets/CMakeLists.txt
@@ -15,6 +15,8 @@ add_library(
   configurationVector.cpp
   configurationVector.h
   configurationVector.ui
+  dataSource.cpp
+  dataSource.h
   dialog.cpp
   dialog.h
   dialog.ui
diff --git a/src/gui/keywordWidgets/dataSource.cpp b/src/gui/keywordWidgets/dataSource.cpp
new file mode 100644
index 0000000000..612ca98af2
--- /dev/null
+++ b/src/gui/keywordWidgets/dataSource.cpp
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2024 Team Dissolve and contributors
+
+#include "gui/keywordWidgets/dataSource.h"
+#include "gui/keywordWidgets/dialog.h"
+#include "io/fileAndFormat.h"
+#include "main/dissolve.h"
+#include <QComboBox>
+#include <QFile>
+#include <QFileDialog>
+#include <QFileInfo>
+
+DataSourceKeywordWidget::DataSourceKeywordWidget(QWidget *parent, DataSourceKeyword<Data1D> *keyword, CoreData &coreData)
+    : QWidget(parent), KeywordWidgetBase(coreData), keyword_(keyword), coreData_(coreData)
+{
+    // Add QWidget with Box Layout
+    enumOptionsModel_.setData(dataSource_.dataSourceTypes());
+    FileAndFormatKeyword k(dataSource_.externalDataSource(), "end");
+    FileAndFormatKeywordWidget fileAndFormat(&ui_, &k, coreData);
+
+    if (dataSource_.dataName() == "External")
+    {
+        externalLayout_.addWidget(&fileAndFormat);
+        ui_.setLayout(&externalLayout_);
+    }
+    else if (dataSource_.dataName() == "Internal")
+    {
+    }
+}
\ No newline at end of file
diff --git a/src/gui/keywordWidgets/dataSource.h b/src/gui/keywordWidgets/dataSource.h
new file mode 100644
index 0000000000..6ae6d53ea6
--- /dev/null
+++ b/src/gui/keywordWidgets/dataSource.h
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2024 Team Dissolve and contributors
+
+#pragma once
+
+#include "gui/keywordWidgets/base.h"
+#include "gui/keywordWidgets/fileAndFormat.h"
+#include "gui/keywordWidgets/enumOptions.h"
+#include "gui/models/enumOptionsModel.h"
+#include "keywords/fileAndFormat.h"
+#include "io/import/data1D.h"
+#include "math/data1D.h"
+#include "keywords/dataSource.h"
+#include <QVBoxLayout>
+#include <QWidget>
+
+class DataSourceKeywordWidget : public QWidget, public KeywordWidgetBase
+{
+    // All Qt declarations must include this macro
+    Q_OBJECT
+
+    public:
+    DataSourceKeywordWidget(QWidget *parent, DataSourceKeyword<Data1D> *keyword, CoreData &coreData);
+
+    /*
+     * Keyword
+     */
+    private:
+    // Associated keyword
+    DataSourceKeyword<Data1D> *keyword_;
+
+    protected:
+    // mutable coredata source
+    CoreData &coreData_;
+
+    /*
+     * Widgets
+     */
+    private:
+    // Main form declaration
+    QWidget ui_;
+    QVBoxLayout internalLayout_;
+    QVBoxLayout externalLayout_;
+    DataSource<Data1D> dataSource_;
+
+    // Model for enum options
+    EnumOptionsModel enumOptionsModel_;
+
+    private Q_SLOTS:
+
+    Q_SIGNALS:
+    // Keyword data changed
+    //void keywordDataChanged(int flags);
+
+    /*
+     * Update
+     */
+
+    public:
+    // Update value displayed in widget
+    //void updateValue(const Flags<DissolveSignals::DataMutations> &mutationFlags) override;
+    // Update widget values data based on keyword data
+    //void updateWidgetValues(const CoreData &coreData);
+    // Update keyword data based on widget values
+    //void updateKeywordData();
+};
diff --git a/src/gui/keywordWidgets/dataSource.ui b/src/gui/keywordWidgets/dataSource.ui
new file mode 100644
index 0000000000..c306ded454
--- /dev/null
+++ b/src/gui/keywordWidgets/dataSource.ui
@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>DataSourceWidget</class>
+ <widget class="QWidget" name="DataSourceWidget">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>413</width>
+    <height>328</height>
+   </rect>
+  </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="Expanding" vsizetype="Minimum">
+    <horstretch>3</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
+  <property name="font">
+   <font>
+    <pointsize>10</pointsize>
+   </font>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <property name="spacing">
+    <number>2</number>
+   </property>
+   <property name="leftMargin">
+    <number>0</number>
+   </property>
+   <property name="topMargin">
+    <number>0</number>
+   </property>
+   <property name="rightMargin">
+    <number>0</number>
+   </property>
+   <property name="bottomMargin">
+    <number>0</number>
+   </property>
+  </layout>
+ </widget>
+ <resources>
+  <include location="../main.qrc"/>
+ </resources>
+ <connections/>
+</ui>
diff --git a/src/gui/keywordWidgets/producers.cpp b/src/gui/keywordWidgets/producers.cpp
index ca0879d644..c6dac8f36c 100644
--- a/src/gui/keywordWidgets/producers.cpp
+++ b/src/gui/keywordWidgets/producers.cpp
@@ -7,6 +7,7 @@
 #include "gui/keywordWidgets/bool.h"
 #include "gui/keywordWidgets/configuration.h"
 #include "gui/keywordWidgets/configurationVector.h"
+#include "gui/keywordWidgets/dataSource.h"
 #include "gui/keywordWidgets/double.h"
 #include "gui/keywordWidgets/dropWidget.h"
 #include "gui/keywordWidgets/enumOptions.h"
diff --git a/src/modules/compare/compare.cpp b/src/modules/compare/compare.cpp
index cf214d5769..038e81aafd 100644
--- a/src/modules/compare/compare.cpp
+++ b/src/modules/compare/compare.cpp
@@ -2,12 +2,20 @@
 // Copyright (c) 2024 Team Dissolve and contributors
 
 #include "modules/compare/compare.h"
+#include "classes/dataSource.h"
 #include "keywords/dataSource.h"
+#include "keywords/fileAndFormat.h"
 #include "keywords/rangeVector.h"
 
 CompareModule::CompareModule() : Module(ModuleTypes::Compare)
 {
-    keywords_.setOrganisation("Options");
+    keywords_.setOrganisation("Options", "Data Sources");
+    keywords_.add<EnumOptionsKeyword<DataSource<Data1D>::DataSourceType>>(
+        "DataType", "Specify whether the data is in Dissolve (Internal) or in the file system (External)", dataType_,
+        DataSource<Data1D>::dataSourceTypes());
+    keywords_.add<FileAndFormatKeyword>("Reference", "F(Q) reference data", referenceData_, "EndReference")
+        ->setEditSignals({KeywordBase::ReloadExternalData, KeywordBase::RecreateRenderables});
+    keywords_.setOrganisation("Options", "Errors");
     keywords_.add<DataSourceKeyword<Data1D>>("Data1D", "Specify one-dimensional test reference data", data1dSources_,
                                              "EndData1D");
     keywords_.add<EnumOptionsKeyword<Error::ErrorType>>("ErrorType", "Type of error calculation to use", errorType_,
diff --git a/src/modules/compare/compare.h b/src/modules/compare/compare.h
index fbbc96ad92..dc94c8b1a4 100644
--- a/src/modules/compare/compare.h
+++ b/src/modules/compare/compare.h
@@ -31,6 +31,9 @@ class CompareModule : public Module
      * Definition
      */
     private:
+    DataSource<Data1D>::DataSourceType dataType_{};
+    // Reference for comparison file and format
+    Data1DImportFileFormat referenceData_;
     // Data stored in the keyword
     std::vector<DataSourceKeyword<Data1D>::DataPair> data1dSources_;
     // Method of error calculation to use