More details about pupils' backgrounds should be taken into account when compiling data for secondary school league tables in England, a study says.
Factors such as ethnicity, free meals and special needs should be considered, the Bristol University report says.
The research claims a fifth of schools would see their national league table position change by over 500 places if such factors were taken into account.
Ministers say they want pupils from all backgrounds to fulfil their potential.
Secondary school league tables in England used to be based on the percentage of pupils getting five GCSEs, including maths and English, at grades A*-C, but in 2016, the Department for Education changed the accountability measures to Attainment 8 and Progress 8.
Attainment 8 measures pupils' grades across eight key subjects, while Progress 8 looks at their progress between the end of primary school (age 11) and the end of Key Stage 4, when they sit their GCSEs (age 16).
It is a "value-added" measure which means that pupils' results at age 16 are compared nationally with the results of other pupils who had similar levels of achievement at age 11, to look at the progress individual children have made.
But researchers at the Centre for Multilevel Modelling, Bristol University, say this measure does not go far enough.
They say schools should be judged on a more contextual Progress 8 measure that takes into account other factors that can play a part in a child's achievement.
Using state school GCSE data for 2018, the study authors compared the government's current Progress 8 measure with an "adjusted" measure that also accounted for the following pupil criteria:
- residential deprivation
- whether they are eligible for free meals
- whether English is their first language
- and whether they have special educational needs.
It found that adjusting for these background factors meant that a fifth of schools would see their ranking in national tables - which show school performance based on government accountability measures - change by over 500 places.
Around half (51%) of schools judged to be "underperforming" against current accountability measures would move out of this category.
"The high-average Progress 8 score seen in London halves when we adjust for pupil background," the report says. "This is principally due to these schools teaching high proportions of high-progress ethnic groups.
"In contrast, the low-average Progress 8 score seen in the north-east improves substantially after adjustment, due to the high proportion of poor pupils taught in this region."
The report concludes: "Given the importance of pupil background in driving schools' scores, the government should revise their current school league tables to include an adjusted Progress 8 measure side-by-side with Progress 8 to present a more informative picture of school performance."
The DfE says Progress 8 is a fair measure which helps parents to choose schools.
It says the measure helps to recognise those schools which are making good progress with lower attaining pupils and to identify those schools not doing enough with a high-performing intake.
But Henri Murison, director of the Northern Powerhouse Partnership, which published the research paper, said the government had not had a consistent focus on improving education standards in the north.
"Unless we devolve more powers and funding, establishing a new northern schools board to oversee currently unaccountable schools commissioners and a centre for what works in schools in disadvantaged areas, we will not be able to close the skills gap - even with much more devolution and increased funding for further education to our Metro Mayors and combined authorities."
Nick Brook, deputy general secretary of the National Association of Head Teachers said: "Test and examination results are only part of the picture when judging a school's performance or a pupil's success.
"A dip in results one year does not necessarily equate to a decline in school effectiveness as cohorts vary annually.
"We therefore encourage all parents to take these results with a pinch of salt when choosing a school for their child."