The new National Admissions Test for Law is putting prospective law students on a more even playing field. Liora Lazarus reports

Imagine shopping for a new laptop. From a distance they all look very similar – black, sleek and shiny – but look closer and you'll find they all have individual features that make them different. Try to pick one based on overall impressions alone and you would probably pick the most eye-catching without any idea if it could do the job required.

This is similar to the job many university law school admissions tutors are asked to do: to pick from thousands of almost identical applications from academic high achievers, all eager to win a place to study undergraduate law. With more than a quarter of all A-level candidates (27%) gaining an A or the new A* grade last year, and competition for university places becoming ever fiercer as government funding for higher education is cut, the task of differentiating between candidates will inevitably become even more difficult.

But rather than inspiring a healthy competition for university places with all students on an even playing field, university admissions have the potential to become biased. Students with the best-presented and most impressive applications, often finely crafted with help from experienced staff at elite schools, have the advantage over others whose education has not given them the same privilege.

To level the educational playing field and make admissions fairer, the National Admissions Test for Law (LNAT) was developed in 2004 by a group of seven universities in an attempt to find a way to learn more about the skills and capabilities of the students applying for places in a more objective, and therefore less biased, way.

Working with a panel of lawyers and legal educators, we developed the two-part test (a multiple-choice section and an essay section) to measure the core skills needed in legal education and the practice of law, including comprehension, interpretation, analysis, synthesis, reasoning and deduction.

This resulted in a 95-minute reading comprehension test with multiple-choice questions based on an argumentative passage of text, such as a newspaper article. As background knowledge of the subject was not required to answer the questions, no student would have the upper hand over their fellow applicants.

Students then pick from a choice of five essay questions based on a current affair or moral debate, such as: 'what disciplinary sanctions should teachers be allowed to use?'. They are given 40 minutes to use their skills in interpretation, analysis and deduction to compile a persuasive argument and demonstrate their ability to argue economically to a conclusion with a good command of written English.

The result of the 42 multiple-choice questions – the LNAT score – and the unmarked essay are supplied to university law schools. They are then used as an assessment tool alongside A-level results (or their global equivalent), UCAS applications and admissions interviews to assist them in identifying the candidates with the most promise for success in the study and practice of law.

By focusing purely on aptitude, those sitting the LNAT cannot be coached to succeed, the result is not swayed by presentation skills or a lack of them, it can't be crammed for and is almost impossible for someone to plagiarise or cheat.

So rather than providing an additional hurdle for students to jump through, the LNAT provides them with an opportunity to show off their natural abilities to the law schools to which they are applying, without fear of being at a social or educational disadvantage.

In the 2009-10 academic year more than 7,000 students from the UK and overseas sat the LNAT. The LNAT does not replace A-levels or their global equivalent but is used in conjunction with formal qualifications, the university application form, the candidate's personal statement and, in some cases, performance at interview. Each LNAT university uses candidates' scores differently to suit its own admissions policy.

As the LNAT benefits both the student and the university, the cost of the test is split, with students asked to contribute £50 towards taking the computer-based test in a European Union-based test centre (£70 for those sitting the test outside the EU), and the university to which they have applied paying the rest. In order to further ensure there is no bias against those from less-privileged backgrounds, bursaries are available for students to have their fee waived, providing they meet the relevant criteria.

The LNAT has also been proven to do its job. Research conducted by the National Foundation for Educational Research (NFER) identified a correlation between LNAT results and academic achievement, suggesting that it is a reliable indicator of students' future academic performance in law. NFER's research also suggested that the longer test format, new for the 2011-12 academic year, will give students an even more accurate indication of the level of their future academic achievement in law.

This ability to identify potential success in law education is something that is not just valued by the LNAT-founding law schools – the Universities of Birmingham, Bristol, Durham, Nottingham and Oxford, together with King's College London and University College London. Others are now following suit, with the University of Glasgow, two overseas universities – National University of Ireland, Maynooth and IE University, an international university based in Spain – and now the University of Manchester incorporating it into their admissions procedures for 2012.

It is important not to forget, though, that the purpose of the LNAT is not just in assisting admissions tutors to make difficult decisions and in widening student participation – it also functions as a method of promoting diversity within the law industry as a whole.

The Legal Services Board recently acknowledged that while the law industry is gradually becoming more diverse, senior positions are still overwhelmingly dominated by white middle-class men, and therefore the issue of progression for women, ethnic minorities and those from less-privileged backgrounds within the industry needs to be addressed.

While the LNAT cannot completely revolutionise class and social bias within the law industry, it is a valuable medium for promoting diversity by virtue of the fact that it enables young people to clear the first hurdle towards entering the profession – that of being selected to study law in the first place.

Liora Lazarus is the LNAT chair and a fellow at St Anne's College, Oxford.