diff --git a/Business/Recommendation/ModelCF.php b/Business/Recommendation/ModelCF.php
index 9f9cda6f2..ff1a6ce04 100644
--- a/Business/Recommendation/ModelCF.php
+++ b/Business/Recommendation/ModelCF.php
@@ -49,15 +49,29 @@ final class ModelCF
      * the multiplication gives a score of how much the user may like that movie.
      * A segnificant amount of attributes are required to calculate a good match
      *
-     * @param Matrix $users A mxa matrix where each "m" defines how much the user likes a certain attribute type and "a" defines different users
-     * @param Matrix $items A bxm matrix where each "b" defines a item and "m" defines how much it belongs to a certain attribute type
+     * @param array<int|string, array<int|float>> $users A mxa matrix where each "m" defines how much the user likes a certain attribute type and "a" defines different users
+     * @param array<int|string, array<int|float>> $items A bxm matrix where each "b" defines a item and "m" defines how much it belongs to a certain attribute type
      *
      * @return array
      *
      * @since 1.0.0
      */
-    public static function score(Matrix $users, Matrix $items) : array
+    public static function score(array $users, array $items) : array
     {
-        return $users->mult($items)->getMatrix();
+        $matrix = [];
+
+        foreach ($users as $uid => $userrow) {
+            foreach ($items as $iid => $itemrow) {
+                $matrix[$uid][$iid] = 0.0;
+
+                foreach ($userrow as $user) {
+                    foreach ($itemrow as $item) {
+                        $matrix[$uid][$iid] += $user * $item;
+                    }
+                }
+            }
+        }
+
+        return $matrix;
     }
 }
diff --git a/tests/Business/Recommendation/ModelCFTest.php b/tests/Business/Recommendation/ModelCFTest.php
new file mode 100644
index 000000000..47418cb38
--- /dev/null
+++ b/tests/Business/Recommendation/ModelCFTest.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace phpOMS\tests\Business\Recommendation;
+
+use phpOMS\Business\Recommendation\ModelCF;
+
+/**
+ * @testdox phpOMS\tests\Business\Recommendation\ModelCFTest: Article affinity/correlation
+ *
+ * @internal
+ */
+final class ModelCFTest extends \PHPUnit\Framework\TestCase
+{
+    public function testScore() : void
+    {
+        self::assertEquals(
+            [
+                [],
+                [],
+                [],
+            ],
+            ModelCF::score(
+                [
+                    [2, 3],
+                    [1, 4],
+                    [3, 3],
+                ],
+                [
+                    [1, 4],
+                    [3, 2],
+                    [2, 2],
+                ]
+            )
+        );
+    }
+}
diff --git a/tests/DataStorage/Database/DataMapperAbstractTest.php b/tests/DataStorage/Database/DataMapperAbstractTest.php
index 4fd37988f..436e88a60 100755
--- a/tests/DataStorage/Database/DataMapperAbstractTest.php
+++ b/tests/DataStorage/Database/DataMapperAbstractTest.php
@@ -169,6 +169,12 @@ final class DataMapperAbstractTest extends \PHPUnit\Framework\TestCase
         $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_has_many_direct')->execute();
         $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_has_many_rel')->execute();
         $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_has_many_rel_relations')->execute();
+
+        $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_has_many_directp')->execute();
+        $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_has_many_relp')->execute();
+        $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_has_many_rel_relationsp')->execute();
+        $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_belongs_to_onep')->execute();
+        $GLOBALS['dbpool']->get()->con->prepare('DROP TABLE test_owns_onep')->execute();
     }
 
     /**