diff --git a/main/gradebook/lib/be/category.class.php b/main/gradebook/lib/be/category.class.php
index b704b148ff..0ffcb4b5c7 100755
--- a/main/gradebook/lib/be/category.class.php
+++ b/main/gradebook/lib/be/category.class.php
@@ -292,7 +292,6 @@ class Category implements GradebookItem
                 // otherwise a special parameter is given to ask explicitely
                 $sql .= " AND (session_id IS NULL OR session_id = 0) ";
             } else {*/
-
             if (empty($session_id)) {
                 $sql .= ' AND (session_id IS NULL OR session_id = 0) ';
             } else {
@@ -326,14 +325,15 @@ class Category implements GradebookItem
                 $sql .= ' '.$order_by;
             }
         }
+
         $result = Database::query($sql);
-        $allcat = array();
 
+        $categories = array();
         if (Database::num_rows($result) > 0) {
-            $allcat = Category::create_category_objects_from_sql_result($result);
+            $categories = Category::create_category_objects_from_sql_result($result);
         }
 
-        return $allcat;
+        return $categories;
     }
 
     /**
@@ -731,7 +731,7 @@ class Category implements GradebookItem
      */
     public function calc_score($stud_id = null, $course_code = '', $session_id = null)
     {
-        // get appropriate subcategories, evaluations and links
+        // Get appropriate subcategories, evaluations and links
         if (!empty($course_code)) {
             $cats  = $this->get_subcategories($stud_id, $course_code, $session_id);
             $evals = $this->get_evaluations($stud_id, false, $course_code);
@@ -782,10 +782,9 @@ class Category implements GradebookItem
         }
 
         if (!empty($links)) {
-            /** @var EvalLink $link */
+            /** @var EvalLink|ExerciseLink $link */
             foreach ($links as $link) {
                 $linkres = $link->calc_score($stud_id);
-
                 if (!empty($linkres) && $link->get_weight() != 0) {
                     $linkweight = $link->get_weight();
                     $link_res_denom = $linkres[1] == 0 ? 1 : $linkres[1];
@@ -1296,14 +1295,23 @@ class Category implements GradebookItem
 
         // 1 student
         if (isset($stud_id)) {
-            // special case: this is the root
+            // Special case: this is the root
             if ($this->id == 0) {
                 return Category::get_root_categories_for_student($stud_id, $course_code, $session_id);
             } else {
-                return Category::load(null,null, $course_code, $this->id, api_is_allowed_to_edit() ? null : 1, $session_id, $order);
+                return Category::load(
+                    null,
+                    null,
+                    $course_code,
+                    $this->id,
+                    api_is_allowed_to_edit() ? null : 1,
+                    $session_id,
+                    $order
+                );
             }
-        } else {// all students
-            // course admin
+        } else {
+            // All students
+            // Course admin
             if (api_is_allowed_to_edit() && !api_is_platform_admin()) {
                 // root
                 if ($this->id == 0) {
diff --git a/main/gradebook/lib/be/evallink.class.php b/main/gradebook/lib/be/evallink.class.php
index 34484703cf..651e6da3ae 100755
--- a/main/gradebook/lib/be/evallink.class.php
+++ b/main/gradebook/lib/be/evallink.class.php
@@ -19,18 +19,26 @@ abstract class EvalLink extends AbstractLink
         parent::__construct();
     }
 
-    // Functions implementing AbstractLink
-
+    /**
+     * @return bool
+     */
     public function has_results()
     {
         $eval = $this->get_evaluation();
+
         return $eval->has_results();
     }
 
-    public function calc_score($stud_id = null)
+    /**
+     * @param int $userId
+     *
+     * @return array
+     */
+    public function calc_score($userId = null)
     {
         $eval = $this->get_evaluation();
-        return $eval->calc_score($stud_id);
+
+        return $eval->calc_score($userId);
     }
 
     public function get_link()
diff --git a/main/gradebook/lib/be/exerciselink.class.php b/main/gradebook/lib/be/exerciselink.class.php
index b5d5db16b8..38e5161e50 100755
--- a/main/gradebook/lib/be/exerciselink.class.php
+++ b/main/gradebook/lib/be/exerciselink.class.php
@@ -221,7 +221,7 @@ class ExerciseLink extends AbstractLink
             if ($student_count == 0) {
                 return null;
             } else {
-                return array ($sum , $student_count);
+                return array($sum, $student_count);
             }
         }
     }
diff --git a/main/gradebook/lib/scoredisplay.class.php b/main/gradebook/lib/scoredisplay.class.php
index 7881352c45..e46f7b8998 100755
--- a/main/gradebook/lib/scoredisplay.class.php
+++ b/main/gradebook/lib/scoredisplay.class.php
@@ -364,9 +364,11 @@ class ScoreDisplay
                 return $this->display_as_div($score).' (' . $this->display_as_percent($score) . ')'.$custom;
             case SCORE_DIV_SIMPLE_WITH_CUSTOM :         // X - Good!
                 $custom = $this->display_custom($score);
+
                 if (!empty($custom)) {
                     $custom = ' - '.$custom;
                 }
+
                 return $this->display_simple_score($score).$custom;
                 break;
             case SCORE_DIV_SIMPLE_WITH_CUSTOM_LETTERS: