Premature babies have a high risk of adverse developmental outcomes. Early intervention approaches are applied to reduce these adverse outcomes or support of developmental delay. Early intervention approaches may vary depending on developmental priorities. While some early intervention methods can consider body structured findings such as posture, tonus, muscle power, others may consider coaching family, enrichment of the environment. The explorer baby program is developed based on the trial and error process. The program tries to find an answer to a unique question: "how trial behavior in infants can be increased and which behaviors of the infants should be supported to increase their trial process?" The Explorer baby program tries to increase exploratory motor behaviors to facilitate development. For this aim, the program tries to explain how a baby learns new skills such as rolling, sitting, babbling, playing peek a boo, etc. in all domains of development while the baby lives in their natural environment. This study aims to investigate the effect of the explorer baby early intervention program.

The aim of the study is to investigate the effect of Explorer Baby Early Intervention Program on explorative motor behaviors, motor, language, and cognitive skills. The study is designed as a randomized controlled trial in which infants and their families are randomly assigned to the intervention group (Explorer Baby) or control group (neurodevelopmental therapy), stratified by birth weeks and educational level of the mother.

There is no developmental support program as standard care in Turkey for premature babies. So that neither intervention nor the control group doesn't take any other support. There will be an average of six intervention sessions during the 6 months intervention period. The assessments will take before intervention (T0), after 3 months after T0 (T1) and after six months after T0 (T2), corrected age one (T3), corrected age two (T4).

Intervention: EXPLORatory motor behavior based Early Intervention Program (Explorer Baby) is a developmental support program for babies and their families. Parents visit the early intervention center with their babies in a variable frequency. The first step of the program is to build up interaction between therapists and parents; worries of parents for the development of their babies, knowledge about child development, knowledge about play behaviors, how babies learn new skills, age-specific requirements of babies, build up interaction with babies and family members, describing blocks for development.

The second step is setting the play in the natural environment working with the family; how do families describe the play? If families want to support the ability of their babies kicking, reaching, rolling, communicate, or social interaction how should they organize the playground? Showing families some examples of enrichment of playground for specific aims.

The third step is observing babies' reactions; how do families motivate their babies for play? How do families encourage their babies for self-starting explorative behaviors? How do parents support making the voice of the baby more if the play context is meaningful for creating a voice? The program doesn't give specific play homework to improve specific skills. The program tries to enrich parents' knowledge about the effect on the behavior of babies in meaningful situations.

The control Group: The control group will take neurodevelopmental therapy. Neurodevelopmental therapy is commonly accepted as traditional therapy.

Inclusion Criteria:

• Born before than 33 weeks

Exclusion Criteria:

• congenital malformations, all levels of asphyxia, intracranial hemorrhage, periventricular leukomalacia.

The study will share the outcomes of statistics by using tables, figures.

The outcomes assessor is masking.