The objective of this randomized study is to test the hypothesis that scores on the Bayley Scales of Infant Development-III (Bayley-III) are higher than scores on the Bayley Scales of Infant Development-II (BSID-II) in the same group of infants who were born very preterm.

The objective of this randomized crossover study is to test the hypothesis that scores on the Bayley Scales of Infant Development-III are higher than scores on the Bayley Scales of Infant Development-II in the same group of infants who were born very preterm. First, however, the investigators must demonstrate that significant "learning" does not occur when the tests are administered 4-8 weeks apart. The investigators hypothesize that scores on the Bayley-III will be higher than scores on the BSID-II, irrespective of the order in which the tests are administered.

Inclusion Criteria:

• Birth weight <2000 grams and <32 weeks
• Corrected age of 18-22 months.

Exclusion Criteria:

• English is not the primary language in the child's home.
• Parent is unable to give informed consent for research participation.
• Parent is unable to commit to returning for follow-up testing in 4-8 weeks.
• Infant has severe medical illness or disability expected to impact his/her ability to participate in testing (ex: blindness, deafness, severe cerebral palsy, autism, tracheostomy).
• No exclusion for economic status, gender, race or ethnicity.
• Participation in a RCT that restricts timing and administration of developmental testing.