diff --git a/src/transformer/utils/get_scaled_score.php b/src/transformer/utils/get_scaled_score.php
index 4b279c2a5..0713ec3c7 100644
--- a/src/transformer/utils/get_scaled_score.php
+++ b/src/transformer/utils/get_scaled_score.php
@@ -35,9 +35,5 @@
  * @return int
  */
 function get_scaled_score($rawscore, $minscore, $maxscore) {
-    if ($rawscore >= 0) {
-        return $rawscore / $maxscore;
-    } else {
-        return $rawscore / $minscore;
-    }
+    return (($rawscore - $minscore) / ($maxscore - $minscore) * 2) - 1;
 }
diff --git a/tests/mod_quiz/attempt_submitted/essay/statements.json b/tests/mod_quiz/attempt_submitted/essay/statements.json
index 6ea2648ca..091be0124 100644
--- a/tests/mod_quiz/attempt_submitted/essay/statements.json
+++ b/tests/mod_quiz/attempt_submitted/essay/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/essay_null_response/statements.json b/tests/mod_quiz/attempt_submitted/essay_null_response/statements.json
index cfc37195f..430d95852 100644
--- a/tests/mod_quiz/attempt_submitted/essay_null_response/statements.json
+++ b/tests/mod_quiz/attempt_submitted/essay_null_response/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/gapselect/statements.json b/tests/mod_quiz/attempt_submitted/gapselect/statements.json
index 39191467a..2995118b3 100644
--- a/tests/mod_quiz/attempt_submitted/gapselect/statements.json
+++ b/tests/mod_quiz/attempt_submitted/gapselect/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/match/statements.json b/tests/mod_quiz/attempt_submitted/match/statements.json
index da00b4e5d..4973daf74 100644
--- a/tests/mod_quiz/attempt_submitted/match/statements.json
+++ b/tests/mod_quiz/attempt_submitted/match/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/multichoice/statements.json b/tests/mod_quiz/attempt_submitted/multichoice/statements.json
index 432e882b6..b35f5995b 100644
--- a/tests/mod_quiz/attempt_submitted/multichoice/statements.json
+++ b/tests/mod_quiz/attempt_submitted/multichoice/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/multichoice_withchoices/statements.json b/tests/mod_quiz/attempt_submitted/multichoice_withchoices/statements.json
index 4c1a38be6..91a1b7091 100644
--- a/tests/mod_quiz/attempt_submitted/multichoice_withchoices/statements.json
+++ b/tests/mod_quiz/attempt_submitted/multichoice_withchoices/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/multichoiceset/statements.json b/tests/mod_quiz/attempt_submitted/multichoiceset/statements.json
index 4eb088886..2caf6d718 100644
--- a/tests/mod_quiz/attempt_submitted/multichoiceset/statements.json
+++ b/tests/mod_quiz/attempt_submitted/multichoiceset/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/multichoiceset_withchoices/statements.json b/tests/mod_quiz/attempt_submitted/multichoiceset_withchoices/statements.json
index adb9a5277..5a9d457c6 100644
--- a/tests/mod_quiz/attempt_submitted/multichoiceset_withchoices/statements.json
+++ b/tests/mod_quiz/attempt_submitted/multichoiceset_withchoices/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/no_questions/statements.json b/tests/mod_quiz/attempt_submitted/no_questions/statements.json
index 49b90b123..f913ed1c6 100644
--- a/tests/mod_quiz/attempt_submitted/no_questions/statements.json
+++ b/tests/mod_quiz/attempt_submitted/no_questions/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/numerical/statements.json b/tests/mod_quiz/attempt_submitted/numerical/statements.json
index f97e330da..a7f8b32e5 100644
--- a/tests/mod_quiz/attempt_submitted/numerical/statements.json
+++ b/tests/mod_quiz/attempt_submitted/numerical/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/randomsamatch/statements.json b/tests/mod_quiz/attempt_submitted/randomsamatch/statements.json
index 698e0d1e8..acb577fb6 100644
--- a/tests/mod_quiz/attempt_submitted/randomsamatch/statements.json
+++ b/tests/mod_quiz/attempt_submitted/randomsamatch/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/shortanswer/statements.json b/tests/mod_quiz/attempt_submitted/shortanswer/statements.json
index 190c0ed04..8f3a25622 100644
--- a/tests/mod_quiz/attempt_submitted/shortanswer/statements.json
+++ b/tests/mod_quiz/attempt_submitted/shortanswer/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/truefalse/statements.json b/tests/mod_quiz/attempt_submitted/truefalse/statements.json
index 138aeca59..e90955b37 100644
--- a/tests/mod_quiz/attempt_submitted/truefalse/statements.json
+++ b/tests/mod_quiz/attempt_submitted/truefalse/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,
diff --git a/tests/mod_quiz/attempt_submitted/unknown_qtype/statements.json b/tests/mod_quiz/attempt_submitted/unknown_qtype/statements.json
index 49b90b123..f913ed1c6 100644
--- a/tests/mod_quiz/attempt_submitted/unknown_qtype/statements.json
+++ b/tests/mod_quiz/attempt_submitted/unknown_qtype/statements.json
@@ -27,7 +27,7 @@
         "raw": 50,
         "min": 0,
         "max": 100,
-        "scaled": 0.5
+        "scaled": 0.0
       },
       "completion": true,
       "success": true,