diff --git a/src/Valitron/Validator.php b/src/Valitron/Validator.php
index 90a9aa1..4496e2d 100644
--- a/src/Valitron/Validator.php
+++ b/src/Valitron/Validator.php
@@ -1,16 +1,14 @@
 <?php
 namespace Valitron;
 
-use InvalidArgumentException;
-
 /**
  * Validation Class
  *
  * Validates input against certain criteria
  *
  * @package Valitron
- * @author Vance Lucas <vance@vancelucas.com>
- * @link http://www.vancelucas.com/
+ * @author  Vance Lucas <vance@vancelucas.com>
+ * @link    http://www.vancelucas.com/
  */
 class Validator
 {
@@ -91,7 +89,7 @@ class Validator
             $langMessages = include $langFile;
             static::$_ruleMessages = array_merge(static::$_ruleMessages, $langMessages);
         } else {
-            throw new \InvalidArgumentException("fail to load language file '$langFile'");
+            throw new \InvalidArgumentException("Fail to load language file '" . $langFile . "'");
         }
     }
 
@@ -325,7 +323,7 @@ class Validator
         if (!is_numeric($value)) {
             return false;
         } elseif (function_exists('bccomp')) {
-            return !(bccomp($params[0], $value, 14) == 1);
+            return !(bccomp($params[0], $value, 14) === 1);
         } else {
             return $params[0] <= $value;
         }
@@ -345,12 +343,35 @@ class Validator
         if (!is_numeric($value)) {
             return false;
         } elseif (function_exists('bccomp')) {
-            return !(bccomp($value, $params[0], 14) == 1);
+            return !(bccomp($value, $params[0], 14) === 1);
         } else {
             return $params[0] >= $value;
         }
     }
 
+    /**
+     * Validate the size of a field is between min and max values
+     *
+     * @param  string $field
+     * @param  mixed  $value
+     * @param  array  $params
+
+     * @return bool
+     */
+    protected function validateBetween($field, $value, $params)
+    {
+        if (!is_numeric($value)) {
+            return false;
+        }
+        if (!isset($params[0]) || !is_array($params[0]) || count($params[0]) !== 2) {
+            return false;
+        }
+
+        list($min, $max) = $params[0];
+
+        return $this->validateMin($field, $value, array($min)) && $this->validateMax($field, $value, array($max));
+    }
+
     /**
      * Validate a field is contained within a list of values
      *
@@ -406,7 +427,26 @@ class Validator
             return false;
         }
 
-        return (strpos($value, $params[0]) !== false);
+        $strict = true;
+        if (isset($params[1])) {
+            $strict = (bool) $params[1];
+        }
+
+        $isContains = false;
+        if ($strict) {
+            if (function_exists('mb_strpos')) {
+                $isContains = mb_strpos($value, $params[0]) !== false;
+            } else {
+                $isContains = strpos($value, $params[0]) !== false;
+            }
+        } else {
+            if (function_exists('mb_stripos')) {
+                $isContains = mb_stripos($value, $params[0]) !== false;
+            } else {
+                $isContains = stripos($value, $params[0]) !== false;
+            }
+        }
+        return $isContains;
     }
 
     /**
diff --git a/tests/Valitron/LangTest.php b/tests/Valitron/LangTest.php
index 7660dba..659d5f1 100644
--- a/tests/Valitron/LangTest.php
+++ b/tests/Valitron/LangTest.php
@@ -44,7 +44,7 @@ class LangTest extends BaseTestCase
 
 	/**
      * @expectedException InvalidArgumentException
-     * @expectedExceptionMessage fail to load language file '/this/dir/does/not/exists/en.php'
+     * @expectedExceptionMessage Fail to load language file '/this/dir/does/not/exists/en.php'
      */
 	public function testLangException()
 	{
diff --git a/tests/Valitron/ValidateTest.php b/tests/Valitron/ValidateTest.php
index 996c4a2..ac3ffca 100644
--- a/tests/Valitron/ValidateTest.php
+++ b/tests/Valitron/ValidateTest.php
@@ -287,6 +287,42 @@ class ValidateTest extends BaseTestCase
         $this->assertFalse($v->validate());
     }
 
+    public function testBetweenValid()
+    {
+        $v = new Validator(array('num' => 5));
+        $v->rule('between', 'num', array(3, 7));
+        $this->assertTrue($v->validate());
+    }
+
+    public function testBetweenInvalid()
+    {
+        $v = new Validator(array('num' => 3));
+        $v->rule('between', 'num', array(5, 10));
+        $this->assertFalse($v->validate());
+    }
+
+    public function testBetweenInvalidValue()
+    {
+        $v = new Validator(array('num' => array(3)));
+        $v->rule('between', 'num', array(5, 10));
+        $this->assertFalse($v->validate());
+    }
+
+    public function testBetweenInvalidRange()
+    {
+        $v = new Validator(array('num' => 3));
+        $v->rule('between', 'num');
+        $this->assertFalse($v->validate());
+
+        $v = new Validator(array('num' => 3));
+        $v->rule('between', 'num', 5);
+        $this->assertFalse($v->validate());
+
+        $v = new Validator(array('num' => 3));
+        $v->rule('between', 'num', array(5));
+        $this->assertFalse($v->validate());
+    }
+
     public function testInValid()
     {
         $v = new Validator(array('color' => 'green'));
@@ -666,8 +702,15 @@ class ValidateTest extends BaseTestCase
 
     public function testContainsValid()
     {
-        $v = new Validator(array('test_string' => 'this is a test'));
-        $v->rule('contains', 'test_string', 'a test');
+        $v = new Validator(array('test_string' => 'this is a Test'));
+        $v->rule('contains', 'test_string', 'Test');
+        $this->assertTrue($v->validate());
+    }
+
+    public function testContainsNonStrictValid()
+    {
+        $v = new Validator(array('test_string' => 'this is a Test'));
+        $v->rule('contains', 'test_string', 'test', false);
         $this->assertTrue($v->validate());
     }
 
@@ -678,6 +721,13 @@ class ValidateTest extends BaseTestCase
         $this->assertFalse($v->validate());
     }
 
+    public function testContainsStrictNotFound()
+    {
+        $v = new Validator(array('test_string' => 'this is a Test'));
+        $v->rule('contains', 'test_string', 'test');
+        $this->assertFalse($v->validate());
+    }
+
     public function testContainsInvalidValue()
     {
         $v = new Validator(array('test_string' => 'this is a test'));
@@ -965,7 +1015,7 @@ class ValidateTest extends BaseTestCase
         }
     }
 
-    public function testcreditCardInvalid()
+    public function testCreditCardInvalid()
     {
         $visa         = array(3539511619543489, 3532949059629052, 3024007171194938, 3929646403373269, 3539135861690622);
         $mastercard   = array(4162057048081965, 4382687859049349, 4484388880142230, 4464941521226434, 4473481232685965);