diff --git a/src/app/components/fragments/content-choice-creator/content-choice-creator.component.html b/src/app/components/fragments/content-choice-creator/content-choice-creator.component.html
index 77e4e73c0d316e7b5c3db97913478e9da59ee60c..39efb1df06858dfa6f12514760859fca5cf825ae 100644
--- a/src/app/components/fragments/content-choice-creator/content-choice-creator.component.html
+++ b/src/app/components/fragments/content-choice-creator/content-choice-creator.component.html
@@ -69,7 +69,7 @@
     </button>
   </div>
 
-  <div *ngIf="!editDialogMode">
+  <div *ngIf="!editDialogMode" fxLayout="row" fxLayoutAlign="center" fxLayoutGap="50px">
     <button mat-raised-button type="submit" color="primary">Submit</button>
     <button mat-raised-button (click)="reset($event)" color="primary">Reset</button>
     <button mat-raised-button *ngIf="lastDeletedDisplayAnswer" (click)="recoverDeletedAnswer($event)" color="primary">
@@ -77,7 +77,7 @@
       deletion
     </button>
   </div>
-  <div *ngIf="editDialogMode">
+  <div *ngIf="editDialogMode" fxLayout="row" fxLayoutAlign="center" fxLayoutGap="50px">
     <button mat-raised-button (click)="editDialogClose($event,'edit')" color="primary">Update</button>
     <button mat-raised-button (click)="editDialogClose($event,'abort')" color="primary">Abort</button>
     <button mat-raised-button (click)="openDeletionContentDialog($event)" color="warn">Delete</button>
diff --git a/src/app/components/fragments/content-choice-participant/content-choice-participant.component.ts b/src/app/components/fragments/content-choice-participant/content-choice-participant.component.ts
index e7c988b7d699362d45fb17dc847db20f963cce69..344593533289ec9047108b97c11b7164337d80fc 100644
--- a/src/app/components/fragments/content-choice-participant/content-choice-participant.component.ts
+++ b/src/app/components/fragments/content-choice-participant/content-choice-participant.component.ts
@@ -93,7 +93,7 @@ export class ContentChoiceParticipantComponent implements OnInit {
     this.answerService.addAnswerChoice({
       id: '',
       revision: '',
-      contentId: this.content.contentId,
+      contentId: this.content.id,
       round: 1,
       selectedChoiceIndexes: []
     } as AnswerChoice).subscribe();
diff --git a/src/app/components/fragments/content-list/content-list.component.ts b/src/app/components/fragments/content-list/content-list.component.ts
index 7f623f975a38718c7e751fd5f7d6770ac90ed046..38cff133558789ad3c98902a0a8b362762f4cec9 100644
--- a/src/app/components/fragments/content-list/content-list.component.ts
+++ b/src/app/components/fragments/content-list/content-list.component.ts
@@ -35,13 +35,13 @@ export class ContentListComponent implements OnInit {
 
   ngOnInit() {
     this.roomId = localStorage.getItem(`roomId`);
-    this.getContents(this.roomId);
+    this.getContent(this.roomId);
   }
 
-  getContents(roomId: string): void {
+  getContent(roomId: string): void {
     this.contentService.getContents(roomId)
-      .subscribe(contents => {
-        this.contents = contents;
+      .subscribe(content => {
+        this.contents = content;
       });
   }
 
@@ -69,7 +69,7 @@ export class ContentListComponent implements OnInit {
     }
 
     this.contentBackup = new ContentChoice(
-      content.contentId,
+      content.id,
       content.revision,
       content.roomId,
       content.subject,
@@ -85,7 +85,7 @@ export class ContentListComponent implements OnInit {
 
   createTextContentBackup(content: ContentText) {
     this.contentBackup = new ContentText(
-      content.contentId,
+      content.id,
       content.revision,
       content.roomId,
       content.subject,
diff --git a/src/app/components/fragments/content-text-participant/content-text-participant.component.ts b/src/app/components/fragments/content-text-participant/content-text-participant.component.ts
index c2130674da8732aeb3fdc64023ee78d5f61c4eca..a81d230fa36c7c1f471bb050f1b0d9a32ffcf1e6 100644
--- a/src/app/components/fragments/content-text-participant/content-text-participant.component.ts
+++ b/src/app/components/fragments/content-text-participant/content-text-participant.component.ts
@@ -44,7 +44,7 @@ export class ContentTextParticipantComponent implements OnInit {
     this.answerService.addAnswerText({
       id: '0',
       revision: '0',
-      contentId: this.content.contentId,
+      contentId: this.content.id,
       round: this.content.round,
       subject: this.content.subject,
       body: this.textAnswer,
diff --git a/src/app/components/fragments/statistics/statistics.component.ts b/src/app/components/fragments/statistics/statistics.component.ts
index 8880c11d8e7864ba6dc3c98a7971762a8cfca9ca..1a69bf7e31cc2fd3f806cb127436b4cf21c0dffa 100644
--- a/src/app/components/fragments/statistics/statistics.component.ts
+++ b/src/app/components/fragments/statistics/statistics.component.ts
@@ -52,11 +52,11 @@ export class StatisticsComponent implements OnInit {
   }
 
   getAnswers(): void {
-    for (const question of this.content) {
-      this.contentAnswerService.getAnswers(question.contentId).subscribe( answer => {
+    for (const c of this.content) {
+      this.contentAnswerService.getAnswers(c.id).subscribe( answer => {
         [].push.apply(this.textAnswers, answer);
       });
-      this.contentAnswerService.getAnswers(question.contentId).subscribe( answer => {
+      this.contentAnswerService.getAnswers(c.id).subscribe( answer => {
         [].push.apply(this.choiceAnswers, answer);
       });
     }
@@ -64,19 +64,19 @@ export class StatisticsComponent implements OnInit {
 
   showStatistic(value) {  // refactor answer class structure for less code and more abstraction
     this.statistics = [];
-    for (const question of this.content) {
+    for (const c of this.content) {
       if (value === '1') {
-        if (question.format === ContentType.TEXT) {
-          const count = this.countTextAnswers(question.contentId);
+        if (c.format === ContentType.TEXT) {
+          const count = this.countTextAnswers(c.id);
           this.statistics.push({
-            name: question.subject, answers: count, percent: count * 100 / this.textAnswers.length,
+            name: c.subject, answers: count, percent: count * 100 / this.textAnswers.length,
           });
         }
       } else {
-        if (question.format === ContentType.CHOICE) {
-          const count = this.countChoiceAnswers(question.contentId);
+        if (c.format === ContentType.CHOICE) {
+          const count = this.countChoiceAnswers(c.id);
           this.statistics.push({
-            name: question.subject, answers: count, percent: count * 100 / this.choiceAnswers.length,
+            name: c.subject, answers: count, percent: count * 100 / this.choiceAnswers.length,
           });
         }
       }
diff --git a/src/app/components/pages/content-carousel-page/content-carousel-page.component.ts b/src/app/components/pages/content-carousel-page/content-carousel-page.component.ts
index 7f356336e88c1d654d9e9637b9f223fc79c0f2b1..88ad6abf428f4c38b3c4d69edce1b42857e5bfdc 100644
--- a/src/app/components/pages/content-carousel-page/content-carousel-page.component.ts
+++ b/src/app/components/pages/content-carousel-page/content-carousel-page.component.ts
@@ -24,7 +24,7 @@ export class ContentCarouselPageComponent implements OnInit {
   ngOnInit() {
     this.route.params.subscribe(params => {
       // ToDo: Check api call
-      /*      this.contentService.getContents(params['roomId']).subscribe(result => {
+      /*      this.contentService.getContent(params['roomId']).subscribe(result => {
               this.contents = result;
             }); */
     });
diff --git a/src/app/models/content-choice.ts b/src/app/models/content-choice.ts
index a9752565624b0e68e7821f72072a9113af4a51bf..44c4e60ce8132d077354d1411d41ba354aac92a2 100644
--- a/src/app/models/content-choice.ts
+++ b/src/app/models/content-choice.ts
@@ -7,7 +7,7 @@ export class ContentChoice extends Content {
   correctOptionIndexes: number[];
   multiple: boolean;
 
-  constructor(contentId: string,
+  constructor(id: string,
               revision: string,
               roomId: string,
               subject: string,
@@ -18,7 +18,7 @@ export class ContentChoice extends Content {
               correctOptionIndexes: number[],
               multiple: boolean,
               format: ContentType) {
-    super(contentId,
+    super(id,
       revision,
       roomId,
       subject,
diff --git a/src/app/models/content-text.ts b/src/app/models/content-text.ts
index 4a0a5db86f20038d5450c63a7db97f0c7a0ce77c..7f095006f1565a0a3885212054e3d81663d88e7e 100644
--- a/src/app/models/content-text.ts
+++ b/src/app/models/content-text.ts
@@ -3,14 +3,14 @@ import { ContentType } from './content-type.enum';
 
 export class ContentText extends Content {
 
-  constructor(contentId: string,
+  constructor(id: string,
               revision: string,
               roomId: string,
               subject: string,
               body: string,
               round: number,
               groups: string[]) {
-    super(contentId,
+    super(id,
       revision,
       roomId,
       subject,
diff --git a/src/app/models/content.ts b/src/app/models/content.ts
index 812413580e559111f45c420c5ab34dfe6134a890..6debe09fad6377c3f5e4abe8af666a765950162b 100644
--- a/src/app/models/content.ts
+++ b/src/app/models/content.ts
@@ -1,7 +1,7 @@
 import { ContentType } from './content-type.enum';
 
 export class Content {
-  contentId: string;
+  id: string;
   revision: string;
   roomId: string;
   subject: string;
@@ -11,7 +11,7 @@ export class Content {
   format: ContentType;
   formatAttributes: Map<string, string>;
 
-  constructor(contentId: string,
+  constructor(id: string,
               revision: string,
               roomId: string,
               subject: string,
@@ -20,7 +20,7 @@ export class Content {
               groups: string[],
               format: ContentType,
               formatAttributes: Map<string, string>) {
-    this.contentId = contentId;
+    this.id = id;
     this.revision = revision;
     this.roomId = roomId;
     this.subject = subject;
diff --git a/src/app/services/http/content.service.ts b/src/app/services/http/content.service.ts
index fbb8a0c591d006ea2a93a37a0d35caa6e74b4a1c..ac6c6d158feade528300a5a2628834013c32e0d8 100644
--- a/src/app/services/http/content.service.ts
+++ b/src/app/services/http/content.service.ts
@@ -35,8 +35,7 @@ export class ContentService extends BaseHttpService {
   addContent(content: Content): Observable<Content> {
     const connectionUrl = this.apiUrl.base + this.apiUrl.content + '/';
     return this.http.post<Content>(connectionUrl,
-      { roomId: content.roomId, subject: content.subject, body: content.body,
-        format: content.format, group: 'preparation' },
+      content,
       httpOptions).pipe(
       catchError(this.handleError<Content>('addContent'))
     );
@@ -53,7 +52,7 @@ export class ContentService extends BaseHttpService {
   }
 
   updateContent(updatedContent: Content): Observable<Content> {
-    const connectionUrl = this.apiUrl.base + this.apiUrl.content + '/' + updatedContent.contentId;
+    const connectionUrl = this.apiUrl.base + this.apiUrl.content + '/' + updatedContent.id;
     return this.http.put(connectionUrl, updatedContent, httpOptions).pipe(
       tap(_ => ''),
       catchError(this.handleError<any>('updateContent'))