It depends NHS OT assessment, involved me filling out a sensory questionnaire. She didn't do any formal assessments, just observed ds playing on a 1:1 basis and tried to get him paint, hands in shaving foam etc. He was about 5 at the time.
At about 8, he had an indi assessment. I Filled out the sensory questionnaire. She assessed
handwriting and drawing. It involved ds writing/drawing what was required of him.
visual processing - eye-hand co-ordination, position in space, visual motor speed balance, visual closure etc. This was a formal assessment, it involved ds having to do was required (copying shapes etc)
gross and fine motor skills - postural tone and joint stability, spatial awareness, motor planning. This was a formal assessment, star jumps etc
Self care and independence skills, again from sensory questionnaire and noted any difficulties she observed.
Sensory processing ie auditory, touch processing, body awareness, balance and motion, planning and ideas - this was done in the form of classroom observation, against my questionnaire.
Play and social interaction skills - observed in classroom.
I told ds he would be seeing an OT and she might ask him some questions or want him to play some games, as she wanted to know how he was getting on.