diff --git a/templates/objectives/skills/tree.html b/templates/objectives/skills/tree.html
index 957df869f1..176863f951 100644
--- a/templates/objectives/skills/tree.html
+++ b/templates/objectives/skills/tree.html
@@ -3,6 +3,8 @@
 {% block header %}
 <style>
     svg {
+      /* width: 50%;
+      height: 50%; */
       width: 25%;
       height: 25%;
     }
@@ -58,7 +60,7 @@
         ]
 
         const dag = d3.dagStratify()(data);
-        const nodeRadius = 20;
+        const nodeRadius = 30;
         const layout = d3
             //
             // Base layout
@@ -165,7 +167,7 @@
             // .attr("font-size", function(d) { return Math.min(2 * d.r, (2 * d.r - 8) / this.getComputedTextLength() * 24) + "px"; })
             // .attr("font-size", function(d) {return (1 / d.data.id.length) * 60;})
             // .attr("font-size", set_font_size(d.data.id))
-            .attr("font-size", function(d) {return (1 / compute_font_size(d.data.id)) * 60;})
+            .attr("font-size", function(d) {return (1 / compute_font_size(d.data.id)) * 80;})
             .attr("font-weight", "bold")
             .attr("font-family", "sans-serif")
             .attr("text-anchor", "middle")
diff --git a/ultron/objective/management/commands/rebuild_tree.py b/ultron/objective/management/commands/rebuild_tree.py
index c10857140d..edce49ff82 100644
--- a/ultron/objective/management/commands/rebuild_tree.py
+++ b/ultron/objective/management/commands/rebuild_tree.py
@@ -13,13 +13,15 @@ from ultron.objective.models import Educative, PrerequisiteClosure
 class Command(BaseCommand):
     def handle(self, *args, **options):
         educative_list = Educative.objects.all()
-
+        count = 0
         for educative in educative_list:
+            count += 1
+            print(str(count)  + ' - Traitement de ' + str(educative.long_label))
             breadcrumb = educative.breadcrumb()
 
             for path in range(0, len(breadcrumb)):
                 tree = set(PrerequisiteClosure.objects.filter(descendant=educative, path=path))
-    
+
                 for position, ancestor in enumerate(breadcrumb[path]):
                     tree_path, _ = PrerequisiteClosure.objects.get_or_create(
                         ancestor=ancestor, descendant=educative, level=position, path=path
diff --git a/ultron/objective/tests.py b/ultron/objective/tests.py
new file mode 100644
index 0000000000..fad87b94a6
--- /dev/null
+++ b/ultron/objective/tests.py
@@ -0,0 +1,60 @@
+from django.test import TestCase
+from ultron.objective.models import Educative
+
+
+class EducativeTestCase(TestCase):
+
+
+    def setUp(self):
+        """
+        Structure finale :
+            1 -> 2
+            1           ->         6
+                    3 -> 4 -> 5 -> 6 -> 7
+            1 -> 2              ->           9
+                    3 -> 4 -> 5 -> 6 -> 7 -> 9
+        """
+        # 1 et 3 Eductative sans pre-requis
+        educ_1 = Educative.objects.create(long_label="1/2 vrille", difficulty=0.1, level=1, rank=1)
+        educ_3 = Educative.objects.create(long_label="4 pattes", difficulty=0.1, level=1, rank=1)
+
+        educ_2 = Educative.objects.create(long_label="tour", difficulty=0.2, level=1, rank=2)
+        educ_2.prerequisites.add(educ_1)
+
+        educ_4 = Educative.objects.create(long_label="Ventre", difficulty=0.1, level=1, rank=1)
+        educ_4.prerequisites.add(educ_3)
+        educ_5 = Educative.objects.create(long_label="3/4 Avant /", difficulty=0.3, level=1, rank=1)
+        educ_5.prerequisites.add(educ_4)
+        educ_6 = Educative.objects.create(long_label="Avant /", difficulty=0.6, level=1, rank=1)
+        educ_6.prerequisites.add(educ_5)
+        educ_7 = Educative.objects.create(long_label="Barani /", difficulty=0.6, level=1, rank=1)
+        educ_7.prerequisites.add(educ_6)
+        educ_7.prerequisites.add(educ_1)
+        # educ_8 = Educative.objects.create(long_label="3/4 Avant vrille", difficulty=0.5, level=1, rank=1)
+        # educ_8.prerequisites.add(educ_6)
+        # educ_8.prerequisites.add(educ_2)
+        educ_9 = Educative.objects.create(long_label="Rudy", difficulty=0.8, level=1, rank=1)
+        educ_9.prerequisites.add(educ_2)
+        educ_9.prerequisites.add(educ_7)
+
+    def test_educative_breadcrumb(self):
+
+        # Cas "None" d'un objet qui n'a pas de prerequis
+        educ_1 = Educative.objects.get(long_label="1/2 vrille")
+        self.assertEqual(educ_1.breadcrumb(), [[educ_1]])
+
+        # Cas simplise : un objet avec un seul encetre
+        educ_2 = Educative.objects.get(long_label="tour")
+        self.assertEqual(educ_2.breadcrumb(), [[educ_2, educ_1]])
+
+        # Cas simple : chaque skill n'a qu'un seul encetre
+        educ_3 = Educative.objects.get(long_label="4 pattes")
+        educ_4 = Educative.objects.get(long_label="Ventre")
+        educ_5 = Educative.objects.get(long_label="3/4 Avant /")
+        educ_6 = Educative.objects.get(long_label="Avant /")
+        educ_7 = Educative.objects.get(long_label="Barani /")
+        self.assertEqual(educ_7.breadcrumb(), [[educ_7, educ_1], [educ_7, educ_6, educ_5, educ_4, educ_3]])
+
+        # Cas plus complexe : l'éduc 8 a deux encetres qui ont chacun une lignée d'encêtres
+        educ_9 = Educative.objects.get(long_label="Rudy")
+        self.assertEqual(educ_9.breadcrumb(), [[educ_9, educ_7, educ_1], [educ_9, educ_7, educ_6, educ_5, educ_4, educ_3], [educ_9, educ_2, educ_1]])
\ No newline at end of file
diff --git a/ultron/objective/urls.py b/ultron/objective/urls.py
index 80080ed6fc..ea507f1a69 100644
--- a/ultron/objective/urls.py
+++ b/ultron/objective/urls.py
@@ -12,6 +12,7 @@ skill_urlpatterns = [
     path(r"search/", views.skill_listing),
     path(r"<int:skill_id>/", views.skill_details, name="skill_details"),
     path(r"<int:skill_id>/tree/", views.skill_tree, name="skill_tree"),
+    path(r"prerequisiteless/", views.skill_without_prerequisite_listing, name="skill_without_prerequisite"),
     path(r"", views.skill_listing, name="skill_list"),
 ]
 
diff --git a/ultron/objective/views.py b/ultron/objective/views.py
index b24183e541..67edf98c8a 100644
--- a/ultron/objective/views.py
+++ b/ultron/objective/views.py
@@ -36,11 +36,20 @@ def skill_lookup(request):
             {"ID": x.id, "Name": str(x), "Notation": x.notation} for x in model_results
         ]
 
-    # json = simplejson.dumps(results)
-    # return HttpResponse(json, content_type="application/json")
     return JsonResponse(results, safe=False)
 
 
+@login_required
+@require_http_methods(["GET"])
+def skill_without_prerequisite_listing(request):
+    """
+    Récupère la liste des skills suivant un pattern si celui-ci est définit.
+    """
+    skill_list = Skill.objects.filter(prerequisites=None)
+    context = {"skill_list": skill_list}
+    return render(request, "objectives/skills/list.html", context)
+
+
 @login_required
 @require_http_methods(["GET"])
 def skill_listing(request, field=None, expression=None, value=None, level=None):
@@ -61,7 +70,7 @@ def skill_listing(request, field=None, expression=None, value=None, level=None):
         kwargs = {"{0}__{1}".format(field, expression): value}
         skill_list = Skill.objects.filter(**kwargs)
     elif level is not None:
-        skill_list = Skill.objects.filter
+        skill_list = Skill.objects.filter(level=level)
     else:
         skill_list = Skill.objects.all()
 
@@ -76,19 +85,9 @@ def skill_tree(request, skill_id):
     """
     skill = get_object_or_404(Skill, pk=skill_id)
     node_dict = {}
-    # node_list[skill] = list(skill.prerequisites.all())
-
     skill_closure = PrerequisiteClosure.objects.filter(descendant=skill)
     for closure in skill_closure:
         node_dict[closure.ancestor] = closure.ancestor.prerequisites.all()
-        # if closure.descendant != closure.ancestor:
-        #     print(closure)
-    # print(node_dict)
-
-    # edge_list = {}
-    # for skill in node_list.values():
-    #     edge_list[skill.long_label] = list(skill.prerequisites.all())
-    # print(edge_list)
 
     context = {"skill": skill, "node_dict": node_dict}
     return render(request, "objectives/skills/tree.html", context)