"A local authority much have regard to the desirability of such a formula being simple, objective, measurable, predictable in effect and clearly expressed" (The School Funding (Wales) Regulations 2010, Section 10 paragraph 2)

Did the authority provide a written explanation of the Gwynedd funding formula? Yes, the authority provided the written explanation of the funding formula for each category of school.

Is the formula measurable? Is it predictable? Yes. With the necessary specific information related to a school it ought to be possible to work out how a school's funding was arrived at. 

"The regulations require that 70 per cent of the funding must be distributed on the basis of pupil numbers. (School Funding in Wales Research Briefing August 2018)

Is 70% of school funding based on pupil numbers? The Gwynedd formula does not take a pupil-based approach but instead the number of students is used to indicate the number of teachers required and from that required funding is determined. Gwynedd Council also provided information on the funding allocations for each school. So it is possible to see how each school's budget is calculated. It is not possible however to see clearly and easily whether 70% of the school funding is based on pupil numbers. 

There is no clear indication that Gwynedd is ensuring "the same funding for pupils of the same age irrespective of the nature of the school which they attend" (The School Funding (Wales) Regulations 2010, Section 23 paragraph 1b).

References: Data Sources for Gwynedd