<?php
/**
 * ZnZend
 *
 * @author Zion Ng <zion@intzone.com>
 * @link   http://github.com/zionsg/ZnZend for canonical source repository
 */

namespace ZnZend\Captcha\Service;

/**
 * Interface for services providing question/answer for ZnZend\Captcha\Question adapter
 */
interface QuestionServiceInterface
{
    /**
     * Generate new set of question and answer
     *
     * @return QuestionServiceInterface
     */
    public function generate();

    /**
     * Get current question
     *
     * @return string
     */
    public function getQuestion();

    /**
     * Get answer to current question
     *
     * @return string
     */
    public function getAnswer();
}

<?php
/**
 * ZnZend
 *
 * @author Zion Ng <zion@intzone.com>
 * @link   http://github.com/zionsg/ZnZend for canonical source repository
 */

namespace ZnZend\Captcha\Service;

/**
 * Interface for services providing question/answer for ZnZend\Captcha\Question adapter
 */
interface QuestionServiceInterface
{
    /**
     * Generate new set of question and answer
     *
     * @return QuestionServiceInterface
     */
    public function generate();

    /**
     * Get current question
     *
     * @return string
     */
    public function getQuestion();

    /**
     * Verify user input with current answer
     *
     * This is preferred over a getAnswer() method as the developer would not
     * need to know the implementation details in order to compare the answers.
     *
     * @param  mixed $value
     * @return bool
     */
    public function verify($value);
}

--- 
+++ 
@@ -28,13 +28,9 @@
     public function getQuestion();
 
     /**
-     * Verify user input with current answer
+     * Get answer to current question
      *
-     * This is preferred over a getAnswer() method as the developer would not
-     * need to know the implementation details in order to compare the answers.
-     *
-     * @param  mixed $value
-     * @return bool
+     * @return string
      */
-    public function verify($value);
+    public function getAnswer();
 }
Use getAnswer() instead of verify() as service does not cache answers