New learning coaches for pupils aged 14-19 will support teachers, not supplant them, say ministers.
But Assembly members have raised concerns about who will employ, manage and fund them.
Around 240 people are currently training as learning coaches, as part of the learning pathways reforms of the 14-19 curriculum.
Education, lifelong learning and skills minister Jane Davidson said learning coaches were key to maximising pupils' ability to learn.
Speaking at last week's meeting of the Assembly's education committee, she claimed the reforms would transform 14-19 provision.
But Plaid Cymru's Janet Ryder, shadow education minister, asked whether coaches would be employed by schools or colleges.
She added: "To whom will they be accountable within a school or college? What is the line management? And what will be the ratio of coaches to students?"
Deputy minister Christine Chapman said coaches would support teachers, not supplant them. Arrangements would be decided once the current pound;800,000 pilot scheme has been evaluated. Accountability will vary according to the setting, she added.
"We are putting a lot of money into 14-19 networks," she said. "This will be an entitlement for all young people, including those who have entered employment."