diff --git a/packages/core/src/definitions/activityFromBot.js b/packages/core/src/definitions/activityFromBot.js
new file mode 100644
index 0000000000..8570b01d2d
--- /dev/null
+++ b/packages/core/src/definitions/activityFromBot.js
@@ -0,0 +1 @@
+export default activity => activity && activity.from.role === 'bot'
diff --git a/packages/core/src/sagas/incomingActivitySaga.js b/packages/core/src/sagas/incomingActivitySaga.js
index 1f81e12fe3..6a4fd759a6 100644
--- a/packages/core/src/sagas/incomingActivitySaga.js
+++ b/packages/core/src/sagas/incomingActivitySaga.js
@@ -5,21 +5,15 @@ import {
 
 import updateIn from 'simple-update-in';
 
-import observeEach from './effects/observeEach';
-import whileConnected from './effects/whileConnected';
-
 import incomingActivity from '../actions/incomingActivity';
 import setSuggestedActions from '../actions/setSuggestedActions';
 
-function last(array, predicate) {
-  for (let i = array.length - 1; i >= 0; i--) {
-    const item = array[i];
+import activityFromBot from '../definitions/activityFromBot';
 
-    if (predicate.call(array, item)) {
-      return item;
-    }
-  }
-}
+import observeEach from './effects/observeEach';
+import whileConnected from './effects/whileConnected';
+
+import { ofType as activitiesOfType } from '../selectors/activities';
 
 export default function* () {
   yield whileConnected(observeActivity);
@@ -32,11 +26,10 @@ function* observeActivity(directLine, userID) {
     yield put(incomingActivity(activity));
 
     // Update suggested actions
-    const { activities } = yield select();
-    const lastMessageActivity = last(activities, ({ type }) => type === 'message');
+    const messageActivities = yield select(activitiesOfType('message'));
+    const lastMessageActivity = messageActivities[messageActivities.length - 1];
 
-    // TODO: [P2] Consider using "definitions/activityFromBot"
-    if (lastMessageActivity && lastMessageActivity.from.role === 'bot') {
+    if (activityFromBot(lastMessageActivity)) {
       const { suggestedActions: { actions } = {} } = lastMessageActivity;
 
       yield put(setSuggestedActions(actions));
diff --git a/packages/core/src/sagas/markAllAsSpokenOnStopSpeakActivitySaga.js b/packages/core/src/sagas/markAllAsSpokenOnStopSpeakActivitySaga.js
index 79b1ca10ef..84f9617830 100644
--- a/packages/core/src/sagas/markAllAsSpokenOnStopSpeakActivitySaga.js
+++ b/packages/core/src/sagas/markAllAsSpokenOnStopSpeakActivitySaga.js
@@ -4,21 +4,21 @@ import {
   takeEvery
 } from 'redux-saga/effects';
 
-import speakingActivity from '../definitions/speakingActivity';
-
 import { STOP_SPEAKING_ACTIVITY } from '../actions/stopSpeakingActivity';
 import markActivity from '../actions/markActivity';
 
+import speakingActivity from '../definitions/speakingActivity';
+
+import { of as activitiesOf } from '../selectors/activities';
+
 export default function* () {
   yield takeEvery(STOP_SPEAKING_ACTIVITY, markAllAsSpoken);
 }
 
 function* markAllAsSpoken() {
-  const { activities } = yield select();
+  const speakingActivities = yield select(activitiesOf(speakingActivity));
 
-  for (let activity of activities) {
-    if (speakingActivity(activity)) {
-      yield put(markActivity(activity, 'speak', false));
-    }
+  for (let activity of speakingActivities) {
+    yield put(markActivity(activity, 'speak', false));
   }
 }
diff --git a/packages/core/src/sagas/postActivitySaga.js b/packages/core/src/sagas/postActivitySaga.js
index 64ee2675e9..8218c93a3c 100644
--- a/packages/core/src/sagas/postActivitySaga.js
+++ b/packages/core/src/sagas/postActivitySaga.js
@@ -9,13 +9,15 @@ import {
   takeEvery
 } from 'redux-saga/effects';
 
-import sleep from '../utils/sleep';
-
 import observeOnce from './effects/observeOnce';
 import whileConnected from './effects/whileConnected';
 
+import languageSelector from '../selectors/language';
+import sendTimeoutSelector from '../selectors/sendTimeout';
+
 import deleteKey from '../utils/deleteKey';
 import getTimestamp from '../utils/getTimestamp';
+import sleep from '../utils/sleep';
 import uniqueID from '../utils/uniqueID';
 
 import {
@@ -38,7 +40,7 @@ export default function* () {
 }
 
 function* postActivity(directLine, userID, numActivitiesPosted, { meta: { method }, payload: { activity } }) {
-  const locale = yield select(({ language }) => language);
+  const locale = yield select(languageSelector);
   const { attachments, channelData: { clientActivityID = uniqueID() } = {} } = activity;
 
   activity = {
@@ -96,7 +98,7 @@ function* postActivity(directLine, userID, numActivitiesPosted, { meta: { method
     //   - Direct Line service only respond on HTTP after bot respond to Direct Line
     // - Activity may take too long time to echo back
 
-    const sendTimeout = yield select(({ sendTimeout }) => sendTimeout);
+    const sendTimeout = yield select(sendTimeoutSelector);
 
     const { send: { echoBack } } = yield race({
       send: all({
diff --git a/packages/core/src/sagas/sendTypingOnSetSendBoxSaga.js b/packages/core/src/sagas/sendTypingOnSetSendBoxSaga.js
index 10801cdea6..e22015a74b 100644
--- a/packages/core/src/sagas/sendTypingOnSetSendBoxSaga.js
+++ b/packages/core/src/sagas/sendTypingOnSetSendBoxSaga.js
@@ -7,11 +7,14 @@ import {
   takeLatest
 } from 'redux-saga/effects';
 
-import whileConnected from './effects/whileConnected';
-
 import { SET_SEND_BOX } from '../actions/setSendBox';
 import { SET_SEND_TYPING } from '../actions/setSendTyping';
 import postActivity from '../actions/postActivity';
+
+import whileConnected from './effects/whileConnected';
+
+import sendTypingSelector from '../selectors/sendTyping';
+
 import sleep from '../utils/sleep';
 
 const SEND_INTERVAL = 3000;
@@ -25,7 +28,7 @@ export default function* () {
 }
 
 function* sendTypingOnSetSendBox() {
-  const { sendTyping } = yield select();
+  const sendTyping = yield select(sendTypingSelector);
 
   if (!sendTyping) {
     yield takeSendTyping(true);
diff --git a/packages/core/src/sagas/startDictateAfterSpeakActivitySaga.js b/packages/core/src/sagas/startDictateAfterSpeakActivitySaga.js
index 029271ca89..852f1a09f2 100644
--- a/packages/core/src/sagas/startDictateAfterSpeakActivitySaga.js
+++ b/packages/core/src/sagas/startDictateAfterSpeakActivitySaga.js
@@ -4,13 +4,15 @@ import {
   takeEvery
 } from 'redux-saga/effects';
 
+import { MARK_ACTIVITY } from '../actions/markActivity';
+import startDictate from '../actions/startDictate';
+
 import speakingActivity from '../definitions/speakingActivity';
 
 import whileConnected from './effects/whileConnected';
 import whileSpeakIncomingActivity from './effects/whileSpeakIncomingActivity';
 
-import { MARK_ACTIVITY } from '../actions/markActivity';
-import startDictate from '../actions/startDictate';
+import { ofID as activitiesOfID } from '../selectors/activities';
 
 export default function* () {
   yield whileConnected(function* () {
@@ -30,11 +32,11 @@ function* startDictateAfterSpeakActivity() {
 }
 
 function* startDictateAfterAllActivitiesSpoken({ payload: { activityID } }) {
-  const { activities } = yield select();
-  const spokenActivity = activities.find(({ id }) => id === activityID);
+  const [spokenActivity] = yield select(activitiesOfID(activityID));
 
   if (
-    spokenActivity.inputHint !== 'ignoringInput'
+    spokenActivity
+    && spokenActivity.inputHint !== 'ignoringInput'
     // Checks if there are no more activities that will be synthesis
     && !activities.some(
       activity => activity.id !== activityID && speakingActivity(activity)
diff --git a/packages/core/src/sagas/submitSendBoxSaga.js b/packages/core/src/sagas/submitSendBoxSaga.js
index 6b29865c37..cf08e5df4f 100644
--- a/packages/core/src/sagas/submitSendBoxSaga.js
+++ b/packages/core/src/sagas/submitSendBoxSaga.js
@@ -4,19 +4,21 @@ import {
   takeEvery
 } from 'redux-saga/effects';
 
-import whileConnected from './effects/whileConnected';
-
 import { SUBMIT_SEND_BOX } from '../actions/submitSendBox';
 import sendMessage from '../actions/sendMessage';
 import setSendBox from '../actions/setSendBox';
 
+import whileConnected from './effects/whileConnected';
+
+import sendBoxValueSelector from '../selectors/sendBoxValue';
+
 export default function* () {
   yield whileConnected(submitSendBox);
 }
 
 function* submitSendBox() {
   yield takeEvery(SUBMIT_SEND_BOX, function* ({ payload: { method } }) {
-    const { sendBoxValue } = yield select();
+    const sendBoxValue = yield select(sendBoxValueSelector);
 
     if (sendBoxValue) {
       yield put(sendMessage(sendBoxValue, method));
diff --git a/packages/core/src/selectors/activities.js b/packages/core/src/selectors/activities.js
new file mode 100644
index 0000000000..033507d02b
--- /dev/null
+++ b/packages/core/src/selectors/activities.js
@@ -0,0 +1,8 @@
+const activities = ({ activities }) => activities
+
+const of = predicate => state => activities(state).filter(predicate)
+const ofID = targetID => of(({ id }) => id === targetID);
+const ofType = targetType => of(({ type }) => type === targetType);
+
+export default activities
+export { of, ofID, ofType }
diff --git a/packages/core/src/selectors/language.js b/packages/core/src/selectors/language.js
new file mode 100644
index 0000000000..a0805cacab
--- /dev/null
+++ b/packages/core/src/selectors/language.js
@@ -0,0 +1 @@
+export default ({ language }) => language
diff --git a/packages/core/src/selectors/sendBoxValue.js b/packages/core/src/selectors/sendBoxValue.js
new file mode 100644
index 0000000000..1856b80846
--- /dev/null
+++ b/packages/core/src/selectors/sendBoxValue.js
@@ -0,0 +1 @@
+export default ({ sendBoxValue }) => sendBoxValue
diff --git a/packages/core/src/selectors/sendTimeout.js b/packages/core/src/selectors/sendTimeout.js
new file mode 100644
index 0000000000..12b4383623
--- /dev/null
+++ b/packages/core/src/selectors/sendTimeout.js
@@ -0,0 +1 @@
+export default ({ sendTimeout }) => sendTimeout
diff --git a/packages/core/src/selectors/sendTyping.js b/packages/core/src/selectors/sendTyping.js
new file mode 100644
index 0000000000..c90c9813cb
--- /dev/null
+++ b/packages/core/src/selectors/sendTyping.js
@@ -0,0 +1 @@
+export default ({ sendTyping }) => sendTyping