public function validation($data, $files) {
        $errors = parent::validation($data, $files);

        if (signup_captcha_enabled()) {
            $recaptchaelement = $this->_form->getElement('recaptcha_element');
            if (!empty($this->_form->_submitValues['g-recaptcha-response'])) {
                $response = $this->_form->_submitValues['g-recaptcha-response'];
                if (!$recaptchaelement->verify($response)) {
                    $errors['recaptcha_element'] = get_string('incorrectpleasetryagain', 'auth');
                }
            } else {
                $errors['recaptcha_element'] = get_string('missingrecaptchachallengefield');
            }
        }

        $errors += signup_validate_data($data, $files);

        return $errors;
    }