diff --git a/core/lib/Drupal/Core/Entity/Plugin/DataType/Entity.php b/core/lib/Drupal/Core/Entity/Plugin/DataType/Entity.php
index 8526b50..785cde9 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/DataType/Entity.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/DataType/Entity.php
@@ -6,7 +6,6 @@
  */
 
 namespace Drupal\Core\Entity\Plugin\DataType;
-use Drupal\Core\Entity\ContentEntityBase;
 
 /**
  * Defines the base plugin for deriving data types for entity types.
diff --git a/core/lib/Drupal/Core/Field/FieldDefinition.php b/core/lib/Drupal/Core/Field/FieldDefinition.php
index c12c71f..7f760a7 100644
--- a/core/lib/Drupal/Core/Field/FieldDefinition.php
+++ b/core/lib/Drupal/Core/Field/FieldDefinition.php
@@ -73,7 +73,7 @@ public static function create($type) {
   public static function createFromItemType($item_type) {
     // The data type of a field item is in the form of "field_item:$field_type".
     $parts = explode(':', $item_type, 2);
-    return FieldDefinition::create($parts[1]);
+    return static::create($parts[1]);
   }
 
   /**
@@ -346,12 +346,12 @@ public function getMainPropertyName() {
    * https://drupal.org/node/2116341.
    */
   protected function getFieldItemClass() {
-    if ($class = $this->itemDefinition->getClass()) {
+    if ($class = $this->getItemDefinition()->getClass()) {
       return $class;
     }
     else {
       $type_definition = \Drupal::typedDataManager()
-        ->getDefinition($this->itemDefinition->getDataType());
+        ->getDefinition($this->getItemDefinition()->getDataType());
       return $type_definition['class'];
     }
   }
diff --git a/core/lib/Drupal/Core/TypedData/DataDefinition.php b/core/lib/Drupal/Core/TypedData/DataDefinition.php
index a902ef0..4bd9e89 100644
--- a/core/lib/Drupal/Core/TypedData/DataDefinition.php
+++ b/core/lib/Drupal/Core/TypedData/DataDefinition.php
@@ -29,15 +29,15 @@ class DataDefinition implements DataDefinitionInterface, \ArrayAccess {
    *   A new DataDefinition object.
    */
   public static function create($type) {
-    return self::createFromDataType($type);
+    $definition['type'] = $type;
+    return new static($definition);
   }
 
   /**
    * {@inheritdoc}
    */
   public static function createFromDataType($type) {
-    $definition['type'] = $type;
-    return new static($definition);
+    return self::$type($type);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php b/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
index 593c752..7e18ff1 100644
--- a/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
+++ b/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
@@ -29,8 +29,14 @@
   /**
    * Creates a new data definition object.
    *
-   * This method is usually called by the manager; i.e.,
-   * \Drupal\Core\TypedData\TypedDataManager::createDataDefinition().
+   * This method is typically used by
+   * \Drupal\Core\TypedData\TypedDataManager::createDataDefinition() to build a
+   * definition object for an arbitrary data type. When the definition class is
+   * known, it is recommended to directly use the static create() method on that
+   * class instead; e.g.:
+   * @code
+   *   $map_definition = \Drupal\Core\TypedData\MapDataDefinition::create();
+   * @endcode
    *
    * @param string $data_type
    *   The data type, for which a data definition should be created.
diff --git a/core/lib/Drupal/Core/TypedData/ListDataDefinitionInterface.php b/core/lib/Drupal/Core/TypedData/ListDataDefinitionInterface.php
index 4c1be08..1270d83 100644
--- a/core/lib/Drupal/Core/TypedData/ListDataDefinitionInterface.php
+++ b/core/lib/Drupal/Core/TypedData/ListDataDefinitionInterface.php
@@ -21,8 +21,14 @@
   /**
    * Creates a new list data definition for items of the given data type.
    *
-   * This method is usually called by the manager; i.e.,
-   * \Drupal\Core\TypedData\TypedDataManager::createListDataDefinition().
+   * This method is typically used by
+   * \Drupal\Core\TypedData\TypedDataManager::createListDataDefinition() to
+   * build a definition object for an arbitrary item type. When the definition
+   * class is known, it is recommended to directly use the static create()
+   * method on that class instead; e.g.:
+   * @code
+   *   $list_definition = \Drupal\Core\TypedData\ListDataDefinition::create('string');
+   * @endcode
    *
    * @param string $item_type
    *   The item type, for which a list data definition should be created.
diff --git a/core/lib/Drupal/Core/TypedData/TypedDataManager.php b/core/lib/Drupal/Core/TypedData/TypedDataManager.php
index 322ee1b..f8c9ab4 100644
--- a/core/lib/Drupal/Core/TypedData/TypedDataManager.php
+++ b/core/lib/Drupal/Core/TypedData/TypedDataManager.php
@@ -142,7 +142,7 @@ public function create(DataDefinitionInterface $definition, $value = NULL, $name
    * E.g., if a definition for a map is to be created, the following code
    * could be used instead of calling this method with the argument 'map':
    * @code
-   *   $map_definition = \Drupal\Core\TypedData\MapDefinition::create();
+   *   $map_definition = \Drupal\Core\TypedData\MapDataDefinition::create();
    * @endcode
    *
    * @param string $data_type
diff --git a/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php b/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php
index 0d53f42..418fd31 100644
--- a/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php
+++ b/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php
@@ -725,7 +725,7 @@ public static function createFromDataType($type) {
   public static function createFromItemType($item_type) {
     // Forward to the field definition class for creating new data definitions
     // via the typed manager.
-    return FieldDefinition::createFromDataType($item_type);
+    return FieldDefinition::createFromItemType($item_type);
   }
 
   /**
diff --git a/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php b/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php
index 4f1b13b..445dc23 100644
--- a/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php
+++ b/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php
@@ -648,7 +648,7 @@ public static function createFromDataType($type) {
   public static function createFromItemType($item_type) {
     // Forward to the field definition class for creating new data definitions
     // via the typed manager.
-    return FieldDefinition::createFromDataType($item_type);
+    return FieldDefinition::createFromItemType($item_type);
   }
 
   public function getDataType() {