Like some sessionals to do the evaluation (6)
I believe the answer is:
assess
'like some sessionals to do the evaluation' is the definition.
I can't judge whether this defines the answer.
'like some sessionals to do the evaluation' is the wordplay.
'like' becomes 'as'.
'some' says to take the initial letters.
'to do the evaluation' becomes 'ess' (I am not sure about this - if you are sure you should believe this answer much more).
The first letter of 'sessionals' is 's'.
'as'+'s'+'ess'='ASSESS'
Can you help me to learn more?
(Other definitions for assess that I've seen before include "Remedy for all ills" , "'Evaluate, appraise (6)'" , "Make estimate or appraisal of" , "Evaluate worth" , "Estimate value (for tax)" .)