diff --git a/src/domain/dataset.js b/src/domain/dataset.js
index 603a64f22..1bfe913ba 100644
--- a/src/domain/dataset.js
+++ b/src/domain/dataset.js
@@ -17,7 +17,8 @@ import {
 } from "ramda";
 
 const defaultState = {
-  datasets: {}
+  datasets: {},
+  diffs:[]
 };
 const defaultItemState = {
   owner: "",
@@ -119,8 +120,10 @@ const valuesFor = (dataset, configuration) => {
 */
 const setDataset = createAction("SET_DATASET");
 const setFilteredDataset = createAction("SET_FILTERED_DATASET");
+const setDatasetDiff = createAction("SET_DATASET_DIFF");
 const removeDataset = createAction("REMOVE_DATASET");
 const removeFilteredDataset = createAction("REMOVE_FILTERED_DATASET");
+const removeDatasetDiff = createAction("REMOVE_DATASET_DIFF");
 const setIsFetching = createAction("SET_IS_FETCHING");
 
 // REDUCERS
@@ -154,6 +157,25 @@ const reducer = handleActions(
       state.datasets[owner].filtered = filtered;
       return { ...state};
     },
+    [setDatasetDiff]: (state, { payload }) => {
+      const start = payload.start;
+      const end = payload.end;
+      const differences = payload.differences
+      const newDiff = {
+        'start': start,
+        'end': end,
+        'differences': differences
+      }
+
+      const idx = state.diffs.findIndex(d => d.start === start && d.end === end);
+
+      if(idx === -1){
+        state.diffs.push(newDiff);
+      } else {
+        state.diffs[idx] = newDiff;
+      }
+      return { ...state};
+    },
     [removeDataset]: (state, { payload }) => {
       const owner = payload.owner;
       if(state.datasets.hasOwnProperty(owner))
@@ -168,6 +190,17 @@ const reducer = handleActions(
 
       return { ...state }
     },
+    [removeDatasetDiff]: (state, { payload }) => {
+      const start = payload.start;
+      const end = payload.end;
+      const idx = state.diffs.findIndex(d => d.start === start && d.end === end);
+
+      if(idx !== -1){
+        state.diffs.splice(idx, 1);
+      }
+
+      return { ...state }
+    },
     [setIsFetching]: (state, { payload }) => {
       const owner = payload.owner;
       const isFetching = !!payload.isFetching;
@@ -183,6 +216,15 @@ const reducer = handleActions(
 
 const selectDataset = (state, owner) => state.dataset.datasets[owner] && state.dataset.datasets[owner].dataset ? state.dataset.datasets[owner].dataset : defaultItemState.dataset;
 const selectFilteredDataset = (state, owner) => state.dataset.datasets[owner] && state.dataset.datasets[owner].filtered ? state.dataset.datasets[owner].filtered : defaultItemState.filtered;
+const selectDatasetDiff = (state, start, end) => {
+  let diff = null;
+  const idx = state.dataset.diffs.findIndex(d => d.start === start && d.end === end);
+
+  if(idx !== -1){
+    diff = state.dataset.diffs[idx].differences;;
+  }
+  return diff;
+}
 const selectConfiguration = (state, owner) => state.dataset.datasets[owner] && state.dataset.datasets[owner].configuration ? state.dataset.datasets[owner].configuration : defaultItemState.configuration;
 const selectMergedConfiguration = (state) => {
   let fields = [];
@@ -223,4 +265,4 @@ const getLastUpdated = (state, owner) => state.dataset.datasets[owner] && state.
 export default reducer;
 
 export { setDataset, selectDataset, removeDataset, setFilteredDataset, selectFilteredDataset, removeFilteredDataset, selectConfiguration, selectMergedConfiguration, selectValues, 
-  selectMergedValues, getFieldId, configurationFor, setIsFetching, getIsFetching, getLastUpdated, valuesFor  };
+  selectMergedValues, getFieldId, configurationFor, setIsFetching, getIsFetching, getLastUpdated, valuesFor, setDatasetDiff, removeDatasetDiff, selectDatasetDiff  };
diff --git a/src/domain/dataset.test.js b/src/domain/dataset.test.js
index ebadb0a05..81473d94f 100644
--- a/src/domain/dataset.test.js
+++ b/src/domain/dataset.test.js
@@ -11,7 +11,10 @@ import {
   selectValues,
   selectMergedValues,
   setIsFetching,
-  getIsFetching
+  getIsFetching,
+  setDatasetDiff,
+  removeDatasetDiff,
+  selectDatasetDiff
 } from "./dataset";
 
 import { combineReducers } from "redux";
@@ -313,5 +316,63 @@ describe("Dataset Reducer", () => {
         done();
       });
     });
+
+    describe("setDatasetDiffs", () => {
+      it("sets the diff between 2 datasets", (done) => {
+        const ds1Owner = uuidv4();
+        const ds2Owner = uuidv4();
+        const ds1 = [
+          { 'uid': "uid1", 'role': { 'role': "role1", 'confidence': 80 } },
+          { 'uid': "uid2", 'role': { 'role': "role1", 'confidence': 80 } }
+        ];
+        const ds2 = [
+          { 'uid': "uid1", 'role': { 'role': "role1", 'confidence': 80 } },
+          { 'uid': "uid2", 'role': { 'role': "role2", 'confidence': 80 } }
+        ];
+        const differences =[{
+          key:"uid2",
+          fields: [{
+            field: { 'path': ["role", "role"], 'displayName': "Role", 'groupable': false },
+            startValue: "role1",
+            endValue: "role2"
+          }]
+        }];     
+
+        const action = setDatasetDiff({ 'start': ds1Owner, 'end': ds2Owner, 'differences': differences });
+        const result = reducer({}, action);
+
+        expect(selectDatasetDiff(result, ds1Owner, ds2Owner)).to.deep.equal(differences);
+
+        done();
+      });
+
+      it("removes the diff between 2 datasets", (done) => {
+        const ds1Owner = uuidv4();
+        const ds2Owner = uuidv4();
+        const ds1 = [
+          { 'uid': "uid1", 'role': { 'role': "role1", 'confidence': 80 } },
+          { 'uid': "uid2", 'role': { 'role': "role1", 'confidence': 80 } }
+        ];
+        const ds2 = [
+          { 'uid': "uid1", 'role': { 'role': "role1", 'confidence': 80 } },
+          { 'uid': "uid2", 'role': { 'role': "role2", 'confidence': 80 } }
+        ];
+        const differences =[{
+          key:"uid2",
+          fields: [{
+            field: { 'path': ["role", "role"], 'displayName': "Role", 'groupable': false },
+            startValue: "role1",
+            endValue: "role2"
+          }]
+        }];     
+
+        const action = removeDatasetDiff({ 'start': ds1Owner, 'end': ds2Owner});
+        const result = reducer({ diffs:[{ 'start': ds1Owner, 'end': ds2Owner, 'differences': differences }] }, action);
+
+        expect(selectDatasetDiff(result, ds1Owner, ds2Owner)).to.equal(null);
+
+        done();
+      });
+    });
   });
 });