Hi, welcome to silkysteps.
You'll need to reflect on the assessments made in your setting of children's development, see if they highlight aspects of your own professional development eg. understanding children's behaviours, schemas, their interests, speaking with parents. How might researching some of these issues help you support children's development?
and yes, a development observation might be a checklist but this type will also be the least favourable way of assessing.
Methods of observation thread will help more xx
Enjoy the site