Roger your location reports as Singapore so I'm not sure if you know much about Agenda for Change but the evalution procedure is detailed here.

One major point is item 12 in the handbook, Freedom to act; band 4 relates to Level 2 which states "Someone is generally available for reference and work may be checked on a sample/random basis" where as band 5 relates to Level 3 which states "Work is managed, rather than supervised, and results/outcomes are assessed at agreed intervals" that's the major reason I wondered if this was actually a trainee position instead?