diff --git a/classes/column.php b/classes/column.php
index 3dd0055..e1eb2d2 100644
--- a/classes/column.php
+++ b/classes/column.php
@@ -52,89 +52,10 @@ class column {
      * @param int $number
      * @param string $name
      */
-    public function __construct(int $id = 0, int $questionid = 0, int $number = 0, string $name = '') {
+    public function __construct(int $questionid = 0, int $number = 0, string $name = '', int $id = 0) {
         $this->questionid = $questionid;
         $this->number = $number;
         $this->name = $name;
         $this->id = $id;
-        $this->column = $this->populate();
-    }
-
-    public function populate(): ?stdClass {
-        if ($this->questionid && $this->name) {
-            $column = new stdClass();
-            $column->questionid = $this->questionid;
-            $column->number = $this->number;
-            $column->name = $this->name;
-            return $column;
-        }
-        return null;
-    }
-
-    /**
-     * Return a column object
-     *
-     * @param string $name
-     * @return stdClass
-     * @throws \dml_exception
-     */
-    public function get_column_by_name(string $name): ?stdClass {
-        if ($name === $this->name) {
-            return $this->column;
-        }
-        return null;
-    }
-
-    /**
-     * Create a column.
-     *
-     * @param int $questionid
-     * @param int $number
-     * @param string $name
-     * @return int
-     */
-    public function create_a_column(int $questionid, int $number, string $name): int {
-        global $DB;
-        $id = $DB->insert_record('qtype_oumatrix_columns',
-                ['questionid' => $questionid, 'number' => $number,'name' => $name ]);
-        return $id;
-    }
-
-    /**
-     * Return column id
-     *
-     * @return int
-     */
-    public function get_id(): int {
-        return $this->id;
-    }
-
-    /**
-     * Return column number
-     *
-     * @return int
-     */
-    public function get_number(): int {
-        return $this->number;
-    }
-
-    /**
-     * Return column name
-     *
-     * @return string
-     */
-    public function get_name(): string {
-        return $this->name;
-    }
-
-    /**
-     * Delete a column.
-     *
-     * @param int $id
-     * @return void
-     */
-    public function delete_a_column(int $id) {
-        global $DB;
-        $DB->delete_records('qtype_oumatrix_columns', ['questionid' => $this->questionid, 'id' => $id]);
     }
 }
diff --git a/classes/row.php b/classes/row.php
index f72f890..dd20785 100644
--- a/classes/row.php
+++ b/classes/row.php
@@ -71,130 +71,5 @@ public function __construct(int $id = 0, int $questionid = 0, int $number = 0, s
         $this->feedbackformat = $feedbackformat;
         $this->id = $id;
     }
-
-    /**
-     * Return a row
-     *
-     * @param int $id
-     * @return stdClass
-     */
-    public function get_a_row_by_id(int $id): ?stdClass {
-        global $DB;
-        if ($row = $DB->get_record('qtype_oumatrix_rows', ['id' => $id])) {
-            return $row;
-        }
-        return null;
-    }
-
-    public function create_default_row(int $questionid,  int $number = 1, string $name = 'row', array $correctanswers = [],
-                    string $feedback = '', int $feedbackformat = 0) {
-        global $DB;
-        $row = new stdClass();
-        $row->questionid = $questionid;
-        $row->number = $number;
-        $row->name = $name;
-        $row->correctanswers = json_encode($correctanswers);
-        $row->feedback = $feedback;
-        $row->feedbackformat = $feedbackformat;
-        return $row;
-    }
-
-    public function create_row(int $questionid,  int $number = 1, string $name = 'row', array $correctanswers = [],
-            string $feedback = '', int $feedbackformat = 0) {
-        $row = new stdClass();
-        $row->questionid = $questionid;
-        $row->number = $number;
-        $row->name = $name;
-        $row->correctanswers = json_encode($correctanswers);
-        $row->feedback = $feedbackformat;
-        $row->feedbackformat = $feedbackformat;
-        return $row;
-    }
-
-    /**
-     * @param array $correctanswers
-     */
-    public function setCorrectanswers(array $correctanswers): void {
-        $this->correctanswers = $correctanswers;
-    }
-
-    /**
-     * Retunr a row.
-     *
-     * @param int $rownumber
-     * @return stdClass
-     * @throws \dml_exception
-     */
-    public function get_a_row(int $rownumber): ?stdClass {
-        global $DB;
-        if ($row = $DB->get_record('qtype_oumatrix_rows', ['questionid' => $this->questionid, 'number' => $rownumber])) {
-            return $row;
-        }
-        return null;
-    }
-
-    /**
-     * Delete a row.
-     *
-     * @param int $rownumber
-     * @return void
-     * @throws \dml_exception
-     */
-    public function delete_a_row(int $rownumber) {
-        global $DB;
-        $DB->delete_records('qtype_oumatrix_rows', ['questionid' => $this->questionid, 'number' => $rownumber]);
-    }
-
-    /**
-     * @return int
-     */
-    public function get_id(): int {
-        return $this->id;
-    }
-
-    /**
-     * @return int
-     */
-    public function get_number(): int {
-        return $this->number;
-    }
-
-    /**
-     * @return string
-     */
-    public function get_name(): string {
-        return $this->name;
-    }
-
-    /**
-     * @return array
-     */
-    public function get_correctanswers(): array {
-        return $this->correctanswers;
-    }
-
-    /**
-     * @return string
-     */
-    public function get_feedback(): string {
-        return $this->feedback;
-    }
-
-    /**
-     * @return int
-     */
-    public function get_feedbackformat(): int {
-        return $this->feedbackformat;
-    }
-
-    /**
-     * Retun number of row.
-     *
-     * @return int
-     */
-    public function get_number_of_rows() {
-        return $this->numberofrows;
-    }
-
 }
 
diff --git a/edit_oumatrix_form.php b/edit_oumatrix_form.php
index 344e1b1..f7fb15a 100644
--- a/edit_oumatrix_form.php
+++ b/edit_oumatrix_form.php
@@ -130,7 +130,8 @@ protected function set_current_settings(): void {
         $this->grademethod = $grademethod;
 
         $columns = optional_param_array('columnname', '', PARAM_TEXT);
-        $this->numcolumns = $columns ? count($columns) : self::COL_NUM_START;
+        $this->numcolumns = $columns ? count($columns) :
+            ($this->question->options->columns ? count($this->question->options->columns) : self::COL_NUM_START);
     }
 
     /**
@@ -146,6 +147,7 @@ public function data_preprocessing($question) {
         $question = parent::data_preprocessing($question);
         $question = $this->data_preprocessing_combined_feedback($question, true);
         $question = $this->data_preprocessing_hints($question, true, true);
+
         $question = $this->data_preprocessing_options($question);
         $question = $this->data_preprocessing_columns($question);
         $question = $this->data_preprocessing_rows($question);
@@ -192,6 +194,7 @@ private function data_preprocessing_columns($question) {
      * @return object The modified data.
      */
     private function data_preprocessing_rows($question) {
+        // preprocess rows.
         if (empty($question->options->rows)) {
             return $question;
         }
@@ -199,14 +202,16 @@ private function data_preprocessing_rows($question) {
         $question->rowname = [];
         foreach ($question->options->rows as $index => $row) {
             $question->rowname[] = $row->name;
-            if ($question->options->inputtype == 'single') {
-                $question->rowanswers[] = $row->correctanswers;
-            } else {
-                $decodedanswers = json_decode($row->correctanswers, true);
-                foreach ($question->options->columns as $key => $column) {
-                    $anslabel = get_string('a', 'qtype_oumatrix', $column->number + 1);
-                    $rowanswerslabel = 'rowanswers' . $anslabel;
-                    $question->$rowanswerslabel[$row->number] = $decodedanswers[$column->name];
+            $decodedanswers = json_decode($row->correctanswers, true);
+            foreach ($question->options->columns as $key => $column) {
+                if (array_key_exists($column->id, $decodedanswers)) {
+                    if ($question->options->inputtype == 'single') {
+                        $anslabel = get_string('a', 'qtype_oumatrix', $column->number + 1);
+                        $question->rowanswers[] = $anslabel;
+                    } else {
+                        $rowanswerslabel = "rowanswers" . $column->number;
+                        $question->$rowanswerslabel[$row->number] = $decodedanswers[$column->id];
+                    }
                 }
             }
             $itemid = (int)$row->id ?? null;
@@ -230,8 +235,12 @@ private function data_preprocessing_rows($question) {
             $key++;
         }
         $question->feedback = $feedback;
+
+        //$this->data_preprocessing_columns($question);
+        //$this->data_preprocessing_rows($question);
         return $question;
     }
+
     protected function get_hint_fields($withclearwrong = false, $withshownumpartscorrect = false) {
         [$repeated, $repeatedoptions] = parent::get_hint_fields($withclearwrong, $withshownumpartscorrect);
         $repeatedoptions['hintclearwrong']['disabledif'] = ['single', 'eq', 1];
diff --git a/question.php b/question.php
index 4cee2f9..5d1dc0a 100644
--- a/question.php
+++ b/question.php
@@ -304,26 +304,17 @@ protected function field(int $rowkey, int $columnkey = 0): string {
     }
 
     public function get_correct_response(): ?array {
-        print_object("get_correct_response");
-        print_object($this);
         $response = [];
         foreach ($this->rows as $row) {
             if ($row->correctanswers != '') {
-                $answer = (int)substr($row->correctanswers[0], 1);
-                $response[$this->field($row->number)] = $this->columns[$answer - 1]->name;
+                $response[$this->field($row->number)] = $this->columns[array_key_first($row->correctanswers)]->name;
             }
         }
-        print_object("=====================================");
-        print_object($response);
         return $response;
     }
 
     public function summarise_response(array $response): ?string {
         $responsewords = [];
-        print_object("summarise_response");
-        print_object($response);
-        print_object($this);
-
         foreach ($this->rows as $row) {
             $fieldname = $this->field($row->number);
             if (array_key_exists($fieldname, $response) && $response[$fieldname]) {
@@ -349,16 +340,6 @@ public function get_validation_error(array $response): string {
     }
 
     public function grade_response(array $response): array {
-        // Retrieve a number of right answers and total answers.
-        //[$numrightparts, $total] = $this->get_num_parts_right($response);
-        //        //        //// Retrieve a number of wrong accent numbers.
-        //        //        //$numpartialparts = $this->get_num_parts_partial($response);
-        //        //        //// Calculate fraction.
-        //        //        //$fraction = ($numrightparts + $numpartialparts - $numpartialparts * $this->accentpenalty)
-        //        //        //        / $total;
-        //        //        //
-        //        //        //return [$fraction, question_state::graded_state_for_fraction($fraction)];
-
         $fraction = 1;
         return [$fraction, question_state::graded_state_for_fraction($fraction)];
     }
diff --git a/questiontype.php b/questiontype.php
index b779d72..cf6ecdb 100644
--- a/questiontype.php
+++ b/questiontype.php
@@ -125,8 +125,8 @@ public function save_question_options($question) {
         $options = $this->save_combined_feedback_helper($options, $question, $context, true);
         $DB->update_record('qtype_oumatrix_options', $options);
 
-        $this->save_columns($question);
-        $this->save_rows($question);
+        $columnslist = $this->save_columns($question);
+        $this->save_rows($question, $columnslist);
         $this->save_hints($question, true);
     }
 
@@ -142,7 +142,7 @@ public function save_columns($formdata) {
             $result->error = get_string('notenoughanswercols', 'qtype_oumatrix',  self::MIN_NUMBER_OF_columns);
             return $result;
         }
-
+        $columnslist = [];
         // Insert column input data.
         for ($i = 0; $i < $numcolumns; $i++) {
             if (trim(($formdata->columnname[$i]) ?? '') === '') {
@@ -151,11 +151,9 @@ public function save_columns($formdata) {
             // Update an existing word if possible.
             $column = array_shift($oldcolumns);
             if (!$column) {
-                $column = new stdClass();
-                $column->questionid = $formdata->id;
-                $column->number = $i;
-                $column->name = $formdata->columnname[$i];
+                $column = new column($formdata->id, $i, $formdata->columnname[$i]);
                 $column->id = $DB->insert_record('qtype_oumatrix_columns', $column);
+                $columnslist[] = $column;
             }
 
             // Remove old columns.
@@ -167,18 +165,19 @@ public function save_columns($formdata) {
                 $DB->delete_records_select('qtype_oumatrix_columns', "id $idssql", $idsparams);
             }
         }
+        return $columnslist;
     }
 
     /**
      *
      * @param object $question This holds the information from the editing form
+     * @param array $columnslist
      * @return void
      * @throws coding_exception
      * @throws dml_exception
      */
-    public function save_rows($question) {
+    public function save_rows($question, $columnslist) {
         global $DB;
-        $context = $question->context;
         $result = new stdClass();
         $oldrows = $DB->get_records('qtype_oumatrix_rows', ['questionid' => $question->id], 'id ASC');
         $numrows = count($question->rowname);
@@ -191,6 +190,7 @@ public function save_rows($question) {
 
         // Insert row input data.
         for ($i = 0; $i < $numrows; $i++) {
+            $answerslist = [];
             if (trim($question->rowname[$i] ?? '') === '') {
                 continue;
             }
@@ -202,27 +202,33 @@ public function save_rows($question) {
                 $questionrow->number = $i;
                 $questionrow->name = $question->rowname[$i];
                 // Prepare correct answers.
-               if($question->inputtype == 'multiple') {
-                    for ($c = 0; $c < count($question->columnname); $c++) {
-                        if ($question->columnname[$c] === '') {
-                            continue;
-                        }
-                        $rowanswerslabel = "rowanswers" . 'a' . ($c + 1);
-
-                        if (!array_key_exists($i, $question->$rowanswerslabel)) {
-                            $answerslist[$question->columnname[$c]] = "0";
-                            continue;
+                if ($question->inputtype == 'multiple') {
+                    //for ($c = 0; $c < count($question->columnname); $c++) {
+                    //    if ($question->columnname[$c] === '') {
+                    //        continue;
+                    //    }
+                    //    $rowanswerslabel = "rowanswers" . 'a' . ($c + 1);
+                    //
+                    //    if (!array_key_exists($i, $question->$rowanswerslabel)) {
+                    //        $answerslist[$question->columnname[$c]] = "0";
+                    for ($c = 0; $c < count($columnslist); $c++) {
+                        if ($question->inputtype == 'multiple') {
+                            $rowanswerslabel = "rowanswers" . 'a' . ($c + 1);
+                            if ($question->columnname[$c] === '' || !array_key_exists($i, $question->$rowanswerslabel)) {
+                                continue;
+                            }
+                            $answerslist[$columnslist[$c]->id] = $question->$rowanswerslabel[$i];
+                        } else {
+                            $columnindex = preg_replace("/[^0-9]/", "", $question->rowanswers[$i]);
+                            $answerslist[$columnslist[$columnindex - 1]->id] = "1";
                         }
-                        $answerslist[$question->columnname[$c]] = $question->$rowanswerslabel[$i];
                     }
                     $questionrow->correctanswers = json_encode($answerslist);
-                } else {
-                    $questionrow->correctanswers = $question->rowanswers[$i] ?? '';
+                    $questionrow->feedback = $question->feedback[$i]['text'];
+                    $questionrow->feedbackitemid = $question->feedback[$i]['itemid'];
+                    $questionrow->feedbackformat = FORMAT_HTML;
+                    $questionrow->id = $DB->insert_record('qtype_oumatrix_rows', $questionrow);
                 }
-                $questionrow->feedback = $question->feedback[$i]['text'];
-                $questionrow->feedbackitemid = $question->feedback[$i]['itemid'];
-                $questionrow->feedbackformat = FORMAT_HTML;
-                $questionrow->id = $DB->insert_record('qtype_oumatrix_rows', $questionrow);
             }
         }
         // Remove old rows.
@@ -316,20 +322,21 @@ protected function initialise_question_rows(question_definition $question, $ques
         if (!empty($questiondata->options->rows)) {
             foreach ($questiondata->options->rows as $row) {
                 $newrow  = $this->make_row($row);
-
-                if ($newrow->get_correctanswers() != '') {
-                    $correctAnswers = $newrow->get_correctanswers();
-                    if( $questiondata->options->inputtype == 'multiple') {
-                        $correctAnswers = [];
-                        $todecode = implode(",", $newrow->get_correctanswers());
-                        $decodedanswers = json_decode($todecode, true);
-                        foreach($questiondata->options->columns as $key => $column) {
-                            if ($decodedanswers != null && array_key_exists($column->name, $decodedanswers)) {
-                                $correctAnswers[$column->number] = $decodedanswers[$column->name];
+                if ($newrow->correctanswers != '') {
+                    $correctAnswers = [];
+                    $todecode = implode(",", $newrow->correctanswers);
+                    $decodedanswers = json_decode($todecode, true);
+                    foreach($questiondata->options->columns as $key => $column) {
+                        if ($decodedanswers != null && array_key_exists($column->id, $decodedanswers)) {
+                            if ($questiondata->options->inputtype == 'single') {
+                                $anslabel = 'a' . $column->number+1;
+                                $correctAnswers[$column->id] = $anslabel;
+                            } else {
+                                $correctAnswers[$column->id] = $decodedanswers[$column->id];
                             }
                         }
                     }
-                    $newrow->setCorrectanswers($correctAnswers);
+                    $newrow->correctanswers = $correctAnswers;
                 }
                 $question->rows[] = $newrow;
             }
@@ -342,18 +349,15 @@ protected function initialise_question_rows(question_definition $question, $ques
      * @param object $questiondata the question data loaded from the database.
      */
     protected function initialise_question_columns(question_definition $question, $questiondata) {
-        if (!empty($questiondata->options->columns)) {
-            foreach ($questiondata->options->columns as $column) {
-                $question->columns[] = $this->make_column($column);
-            }
-        }
+        $question->columns = $questiondata->options->columns;
     }
 
     protected function make_column($columndata) {
-        return new column($columndata->id, $columndata->questionid, $columndata->number, $columndata->name);
+        return new column($columndata->questionid, $columndata->number, $columndata->name, $columndata->id);
     }
 
     public function make_row($rowdata) {
+        // Need to explode correctanswers as it is in the string format.
         return new row($rowdata->id, $rowdata->questionid, $rowdata->number, $rowdata->name,
             explode(',',$rowdata->correctanswers), $rowdata->feedback, $rowdata->feedbackformat);
     }
diff --git a/renderer.php b/renderer.php
index 7f097f9..0e93204 100644
--- a/renderer.php
+++ b/renderer.php
@@ -62,16 +62,8 @@ protected abstract function prompt();
 
     public function formulation_and_controls(question_attempt $qa,
             question_display_options $options) {
-        print_object("Inside renderer.... question ");
-        print_object($qa);
         $question = $qa->get_question();
-        //$response = $question->get_response($qa);
         $response = $qa->get_last_qt_data();
-        print_object("response &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&");
-        print_object($response);
-        //print_object("renderer.... question ");
-        //print_object("renderer.... $response ".$response);
-        //print_object("renderer.... $qa ".$qa);
 
         $inputname = $qa->get_qt_field_name('answer');
         $inputattributes = array(
@@ -232,27 +224,25 @@ public function formulation_and_controls(question_attempt $qa,
     public function get_matrix(question_attempt $qa) {
 
         $question = $qa->get_question();
-        print_object("*******************************************");
-        print_object($question);
         $response = $qa->get_last_qt_data();
-        print_object("*******************************************");
-        print_object($response);
         $caption = "Matrix question";
         $colname[] = null;
         $table = "
-            <table>
+            <table class='generaltable'>
                 <caption class='table_caption'>$caption</caption>
                 <tr>
                     <th scope='col'></th>";
+        $index = 0;
         foreach ($question->columns as $key => $value) {
-            $colname[$key] = $value->get_name();
-            $table .= "<th scope='col'><span id='$colname[$key]' class='answer_col' >$colname[$key]</span></th>";
+            $colname[$index] = $value->name;
+            $table .= "<th scope='col'><span id='$colname[$index]' class='answer_col' >$colname[$index]</span></th>";
+            $index +=  1;
         }
         $table .= "</tr>
         <tr> ";
         $i = 0;
         foreach ($question->rows as $key => $value) {
-            $rowname = $value->get_name();
+            $rowname = $value->name;
             $rowid = 'row_'. $key;
             $table .= "<th scope='col'><span id='$rowid'>$rowname</span></th>";
             for ($j = 0; $j < count($colname); $j++) {
@@ -351,8 +341,7 @@ public function correct_response(question_attempt $qa) {
         $right = [];
         foreach ($question->rows as $row) {
             if ($row->correctanswers != '') {
-                $answer = (int)substr($row->correctanswers[0], 1);
-                $right[] = $row->name . " => " . $question->columns[$answer - 1]->name;
+                $right[] = $row->name . " => " . $question->columns[array_key_first($row->correctanswers)]->name;
             }
         }
         return $this->correct_choices($right);