What is a reasonable period between collecting information and publishing it as data or statistics?
This is the interesting question raised by Dr Keitshepile Setswe, director of the Aids Research Institute at Wits university ("Statistics cannot be manipulated. Releasing results a year after data collection is cause for concern," Star, February 8).
The answer to this depends both on the nature of the information collected and the way in which it is collected.
There are important differences between a small sample survey based on a limited questionnaire sent to respondents by mail, and a population census conducted through personal interview and application of a detailed individual and household questionnaire.
Equally, there are differences between capturing information contained in administrative records (death notification forms, for example) and conducting a fieldwork-based survey of 30 000 households spread across nine provinces (the quarterly labour force survey, for example).
Inevitably, these differences have implications for the time required to capture, process, edit, analyse and publish the information gathered as statistics.
Dr Setswe does not seem to have taken into account these basic distinctions in the statistical cycle from collection to publication.
As a consequence, his comments lack precision and sometimes undermine his own argument.
In an attempt to support his contention that "there is a crisis with statistics, counting, analysis of data and releasing reports in our country", the doctor cites "a few examples in the last two to three years".
"Late in 2002, the inflation rate was wrongly calculated because statisticians at Statistics SA used the wrong data on housing rentals."
"Stats SA confused people who wanted to understand the statistics in The Impact of HIV/Aids on Adult Mortality in South Africa in 2001."
"As if that was not enough, it [Stats SA] got the November manufacturing data wrong."
Leaving to one side the accuracy of these statements, it is hard to see what they add to any discussion of delays between the collection and publication of information.
In two cases, the doctor's examples involve the quality of data (not its timeliness).
The other example cited is difficult to understand, but appears to allege that Stats SA's analysis of a report of another agency "confused people".
Again, it is difficult to see how this relates to timeliness in the release of statistics.
"The results of a national census conducted in 2001 were only released in 2003 - two years after the event!
Leaving aside the error in this contention (the results of Census 2001 were released 18 months after the conclusion of enumeration, not two years), Dr Setswe would no doubt be interested to compare Stats SA's record with those of other national statistical agencies.
For example, recent censuses in Zambia, Ghana, Kenya and Malawi were released between three and three-and-a-half years after completion of enumeration.
Internationally, two years between enumeration and publication of census results is viewed as an achievement.
Dr Setswe also refers to what he calls the "large workforce" and "generous budget" which was made available for Census 2001, questioning why, with these resources, there was what he feels was an unacceptable delay in publishing results.
Again, the doctor's comments do not stand up to scrutiny. In an exercise undertaken during 2003, the results of which were published in this column, the per capita cost of conducting a census, in dollar terms, was established for a number of countries.
South Africa's Census 2001 was conducted at a noticeably lower cost per capita ($2.89) than, for example, Botswana ($3.40), Hungary ($3.70), Namibia ($5.33), Australia ($6.83) Germany ($9) and the US ($22.81).
Dr Setswe's central argument is that "there are generally long delays in releasing key reports required for planning and implementation of projects in the public service in South Africa".
Unfortunately, at least in the case of Stats SA, the examples either do not apply, or demonstrate precisely the opposite of the doctor's contention.
Statistics are best used to cast light on a subject, rather than to shore up preconceived notions. But, as often noted, the inebriated man uses the street light for support, rather than illumination.
So, on occasion, are statistics misused.
Growing debate over the quality and timeliness of statistics indicates a concomitant growth in the use of statistical data for decision making.
However, contributions to that debate will invariably be more constructive if they are informed and based on verified information, rather than speculation presented as fact.
Pali Lehohla is South Africa's statistician-general and head of Statistics SA. For more information on Stats SA and its statistical outputs, visit www.statssa.gov.