public function daleChallDifficultWordCount($strText = false)
    {
        $strText = $this->setText($strText);
        $intDifficultWords = 0;
        $arrWords = explode(' ', Text::lowerCase(preg_replace('`[^A-za-z\' ]`', '', $strText), $this->strEncoding));

        // Fetch Dale-Chall Words
        $arrDaleChall = Resource::fetchDaleChallWordList();

        for ($i = 0, $intWordCount = count($arrWords); $i < $intWordCount; $i++) {
            // Single letters are counted as easy
            if (strlen(trim($arrWords[$i])) < 2) {
                continue;
            }
            if ((!in_array(Pluralise::getPlural($arrWords[$i]), $arrDaleChall)) && (!in_array(Pluralise::getSingular($arrWords[$i]), $arrDaleChall))) {
                $intDifficultWords++;
            }
        }

        return $intDifficultWords;
    }