That is one of the measurements recommended by the Auditor General for Scotland and endorsed this week by the parliamentary education committee in its report on the post-McCrone deal.
Other measures are the quality of educational leadership, teachers'
workload and their mix of skills, work-force morale and recruitment and retention within the profession.
Last year's report by Audit Scotland on the agreement criticised the lack of proper measures to determine whether or not it represented value for money. As a result of that report, the education committee asked Robert Black, the Auditor General, to propose further measures that could be used to assess its impact.
The Scottish Executive gave a commitment to the parliament's audit committee last November that it would consider what it called "proxy measures", such as retention rates and qualitative evidence from inspections, in order to gauge how effectively the agreement was working.
While Mr Black describes this move by the executive as "encouraging", he believes more robust and extensive indicators are necessary.
Members of the education committee said this week they accepted the Auditor General's caveats concerning the difficulties of establishing a direct link between improved pay and conditions and educational attainment.
However, they call on the executive to consider, along with HMIE, whether the Auditor General's proposed new measures might usefully be added to those from inspection evidence.
Overall, however, the MSPs accept that the main element of the agreement was a pay and conditions deal for teachers and that other aspects need to be viewed in that context.
The committee recognises that the agreement has delivered a number of benefits: stability to industrial relations, better financial rewards and support for teachers, reduced class contact time, improved CPD opportunities, the chartered teacher scheme and the induction programme.
"There is a new enthusiasm and willingness to work in collegiate ways which was much less in evidence before the agreement," the report concludes.
However, it adds that the indirect effect of these benefits should be, in the longer term, to enhance learning and teaching and to improve pupil achievement and performance.
While there should be ongoing study into the overall impact of the agreement on the teaching profession, MSPs believe its focus should be on its impact on pupils.
HMIE, in its future study of the agreement, review the impact of reduced class contact time on headteachers and deputes; it be "standard practice" for teachers' CPD provision to become part of their staff reviews;
the executive monitor trends in headteacher and depute head recruitment and come up with a strategy to stave off chronic shortages, which could lead to authorities "poaching" the best headteachers and creating management instability;
research be carried out into the effect of the faculty structures on depart-mental management, support for subject teachers, and pupil learning; work be carried out into the role of support staff who, the committee fears, may not be used to best effect in all authorities and who suffer from low status and rewards.