実際に、チェックボックスの定義が連想配列の使用ができます
$form['high_school']['tests_taken'] = array(
'#type' => 'checkboxes',
'#options' => drupal_map_assoc(
array('sat’=> t('SAT'),
'act' => t('ACT'), )
),
'#title' => t('What standardized tests did you take?'),
'default_value' => array('act') ,
...
),