diff --git a/lib/private/group/backend.php b/lib/private/group/backend.php
index c1de99bca580947457f773a4e85fe5f06bac6f63..38522d0c43c81f7de63b6cb3eb9c775dab75949f 100644
--- a/lib/private/group/backend.php
+++ b/lib/private/group/backend.php
@@ -69,7 +69,7 @@ abstract class OC_Group_Backend implements OC_Group_Interface {
 	/**
 	* @brief Check if backend implements actions
 	* @param int $actions bitwise-or'ed actions
-	* @return boolean
+	* @return bool
 	*
 	* Returns the supported actions as int to be
 	* compared with OC_GROUP_BACKEND_CREATE_GROUP etc.
diff --git a/lib/private/group/database.php b/lib/private/group/database.php
index 18c060e9b22da439910fd60679cc902ca9f84fbd..91baa3140cc39a47db374846ab7d4f6303544e1d 100644
--- a/lib/private/group/database.php
+++ b/lib/private/group/database.php
@@ -215,9 +215,8 @@ class OC_Group_Database extends OC_Group_Backend {
 	 * @brief get the number of all users matching the search string in a group
 	 * @param string $gid
 	 * @param string $search
-	 * @param int $limit
-	 * @param int $offset
 	 * @return int|false
+	 * @throws DatabaseException
 	 */
 	public function countUsersInGroup($gid, $search = '') {
 		$stmt = OC_DB::prepare('SELECT COUNT(`uid`) AS `count` FROM `*PREFIX*group_user` WHERE `gid` = ? AND `uid` LIKE ?');
diff --git a/lib/private/group/dummy.php b/lib/private/group/dummy.php
index 553aae5429104f4ccbac8ac8bd3e344793fafea1..75bab31a337d86435ce55324a80a4518eed83480 100644
--- a/lib/private/group/dummy.php
+++ b/lib/private/group/dummy.php
@@ -31,7 +31,7 @@ class OC_Group_Dummy extends OC_Group_Backend {
 	 * @param string $gid The name of the group to create
 	 * @return bool
 	 *
-	 * Trys to create a new group. If the group name already exists, false will
+	 * Tries to create a new group. If the group name already exists, false will
 	 * be returned.
 	 */
 	public function createGroup($gid) {
@@ -136,18 +136,23 @@ class OC_Group_Dummy extends OC_Group_Backend {
 	}
 
 	/**
-	 * @brief get a list of all groups
+	 * @brief Get a list of all groups
+	 * @param string $search
+	 * @param int $limit
+	 * @param int $offset
 	 * @return array an array of group names
-	 *
-	 * Returns a list with all groups
 	 */
 	public function getGroups($search = '', $limit = -1, $offset = 0) {
 		return array_keys($this->groups);
 	}
 
 	/**
-	 * @brief get a list of all users in a group
-	 * @return array an array of user ids
+	 * @brief Get a list of all users in a group
+	 * @param string $gid
+	 * @param string $search
+	 * @param int $limit
+	 * @param int $offset
+	 * @return array an array of user IDs
 	 */
 	public function usersInGroup($gid, $search = '', $limit = -1, $offset = 0) {
 		if(isset($this->groups[$gid])) {
@@ -159,7 +164,11 @@ class OC_Group_Dummy extends OC_Group_Backend {
 
 	/**
 	 * @brief get the number of all users in a group
-	 * @return int|bool
+	 * @param string $gid
+	 * @param string $search
+	 * @param int $limit
+	 * @param int $offset
+	 * @return int
 	 */
 	public function countUsersInGroup($gid, $search = '', $limit = -1, $offset = 0) {
 		if(isset($this->groups[$gid])) {
diff --git a/lib/private/group/example.php b/lib/private/group/example.php
index cfcc0d245d16c8bca39adf4c8498df542f136a21..76c9ce2433d196c792b2b60053fcad7db67e07b6 100644
--- a/lib/private/group/example.php
+++ b/lib/private/group/example.php
@@ -31,7 +31,7 @@ abstract class OC_Group_Example {
 	 * @param string $gid The name of the group to create
 	 * @return bool
 	 *
-	 * Trys to create a new group. If the group name already exists, false will
+	 * Tries to create a new group. If the group name already exists, false will
 	 * be returned.
 	 */
 	abstract public static function createGroup($gid);
@@ -87,14 +87,15 @@ abstract class OC_Group_Example {
 
 	/**
 	 * @brief get a list of all groups
+	 * @param string $search
+	 * @param int $limit
+	 * @param int $offset
 	 * @return array an array of group names
-	 *
-	 * Returns a list with all groups
 	 */
 	abstract public static function getGroups($search = '', $limit = -1, $offset = 0);
 
 	/**
-	 * check if a group exists
+	 * @brief Check if a group exists
 	 * @param string $gid
 	 * @return bool
 	 */
@@ -102,8 +103,11 @@ abstract class OC_Group_Example {
 
 	/**
 	 * @brief get a list of all users in a group
+	 * @param string $gid
+	 * @param string $search
+	 * @param int $limit
+	 * @param int $offset
 	 * @return array an array of user ids
 	 */
 	abstract public static function usersInGroup($gid, $search = '', $limit = -1, $offset = 0);
-
 }