protected function set_columns() {
		return array(
			'id'          => array(
				'exportable' => true,
				'title'      => __( 'ID', 'lifterlms' ),
				'sortable'   => true,
			),
			'title'       => array(
				'exportable' => true,
				'title'      => __( 'Title', 'lifterlms' ),
				'sortable'   => true,
			),
			'instructors' => array(
				'exportable' => true,
				'filterable' => current_user_can( 'view_others_lifterlms_reports' ) ? $this->get_instructor_filters() : false,
				'title'      => __( 'Instructors', 'lifterlms' ),
			),
			'students'    => array(
				'exportable' => true,
				'title'      => __( 'Students', 'lifterlms' ),
			),
			'progress'    => array(
				'exportable' => true,
				'title'      => __( 'Average Progress', 'lifterlms' ),
				'sortable'   => true,
			),
			'grade'       => array(
				'exportable' => true,
				'title'      => __( 'Average Grade', 'lifterlms' ),
				'sortable'   => true,
			),
		);
	}