Percentages are the most common statistics which lawyers encounter in daily working life. You need to be confident of case facts and recognise potentially incomplete detail or evidence in order to defend your clients’ best interests.
However, how do you see behind the figures blandly quoted in reports and better prepare for dialogue with barristers? Here are reminders of four basic checks as you prepare arguments, engage with expert witnesses or seek out a barrister for advice or representation.
Firstly, be dissatisfied whenever you encounter a percentage in isolation. The figure should always be accompanied by the corresponding absolute number, typically in a format like 40% (200). Only by having the two types of statistic together can you assess the true validity of any interpretation or evidence.
The same point applies when percentage changes are quoted. Imagine a law firm is reported as suffering a 100% increase (a doubling) in bad debt clients this year. However, that figure is insignificant if the company has one thousand clients and the percentage of bad debt clients has risen from 1% to 2% (i.e. 10 to 20). The firm is hardly in peril if those particular 20 people aren’t responsible for the majority of the firm’s income.
Challenge all instances of ‘percentage only’ data in documents or other communications received from the other side in legal proceedings and request absolute figures. (This may also provide a line of questioning for witness testimony.)
Ensure all documents and intended expert evidence for which you or your legal team are responsible do provide percentages + figures as indicated; as a precaution, review again the collective picture created by all the assembled information whenever you add numbers or percentages to the original material.
Secondly, be aware that percentages can disguise low and unconvincing numbers when they are expressed through visual means such as pie charts or bar line graphs. These methods of communicating information may appear particularly within expert evidence.
To emphasise my point, compare the two sets of numbers below which give rise to identical pie charts. If these figures are uniform rate billing time then surely law firms would much prefer the second set!
|Percentage||Absolute number - set 1||Absolute number - set 2|
55 11 1,100
Where absolute numbers are low then a wider context is required: is 11 a greater number than might be reasonably expected? How do you know? Big questions must follow small numbers wherever percentages are involved.
Ensure that all visual presentations for which you, your legal team and witnesses are responsible include both percentages and numbers (in recommended format) on the chart or graph at the appropriate sections. Alternatively make them available in a list placed alongside the chart or graph.
Request the same of the other side in communications. DO NOT try to present a whole series of figures and percentages in a turgid paragraph of text. A simple table such as that demonstrated above relays figures far more readily with a minimum of additional explanation and a maximum impression of brisk efficiency.
Thirdly, be alert to ‘editorialising’ by scrutinising wording which accompanies the percentages and numbers. Watch out for ‘only’, ‘just’, ‘hardly more/less than’, ‘barely’, ‘similar to’ or equivalents. More blatant phrases include ‘significantly worse/better than’ and ‘obviously this means…’.
It can be helpful to copy a document and highlight or delete the editorialising words in order to clinically examine the values cited there. Any discrepancy between the editorialising document’s conclusion and your own may suggest additional lines of enquiry or questions to formulate.
Sometimes a text can reveal editorial bias by the inconsistency of statements in the same document or article. Consider:
‘X significantly outperforms Y by more than 1%’‘X is virtually the same as Y with the latter only achieving a 3% higher performance’
It is reasonable to conclude that the author favours X over Y. Here, extract and lay side-by-side the comparative statements drawn from different parts of the text to identify inconsistencies. They too will require further investigation.
Fourthly, ask, 'What else is happening in the background that is linked to these percentages and numbers?' For example, two law firms (assuming each is the only one in its respective catchment area) experience approximately 1,400% growth over a decade.
|Law Firm||Number of clients 2001||Population 2001||Number of clients 2011||Population 2011|
Alpha law firm seems far less impressive than Zeta based on the absolute numbers that accompany the percentage. Zeta, however, is located in an area that went from 10,000 to 800,000 population - explosive urban growth - in the same period. In the light of this additional information, how effective are the two firms in marketing their services within their communities?
Even with a simple cited percentage + number investigate the wider context if that is not explicitly provided. Do the figures reflect expected and realistic rates? Have they been gathered using methods selected according to normal protocols? These are key baseline questions for commercial and employment law in particular. In making follow-up enquiries, be wary of the answer 'there is no evidence’. There may be no evidence because no-one has actively looked for it. Ruthlessly request an explanation of what has been undertaken to confirm there really isn’t anything further to pursue.
Percentages can create pitfalls for the unwary and unfocused but this list of basic checks provides an effective route around them. In sidestepping the traps you will also convey a message concerning the standards to which you work and strengthen the appreciative confidence of your clients - vital advantages for anyone facing the competition implications of the Legal Services Act.
Alan Wood is Director of Clear Thinking Clear Profit, a management consultancy/training business which specialises in critical thinking skills