Sue,
Chris Gallagher had an article published in the Guardian in 2000 with the
following text :
"The Bradford system of scoring sickness absence, variously known as the
Bradford Formula, Index or Score, aims to measure the disruption caused by
persistent short spells of absence, which are perceived as being more costly
in some circumstances than occasional, longer spells of sickness.
Bradford combines measures of both frequency and duration of absence, with a
greater stress placed on frequency. The formula S2D or S x S x D, is used to
calculate a score or index for a given period, (usually a rolling year),
where S is the number of spells of absence, and D is the aggregate number of
days absent.
This results in employees with the same amount of sick leave but different
numbers of absences having widely disparate scores. For example, someone
absent for 25 days over one absence scores 25, while someone with the same
number of days over 3 absences scores 225 and someone else with 6 absences
scores 900 for their 25 days off, more than 2.5 times the score of someone
absent for the entire rolling year.
Typically, an employer will set a threshold score beyond which the
personnel department or occupational health department will become involved.
Other methods of measuring absence also use formulae to calculate absence
scores and also enjoy wide currency. These include:
Overall absence rate Number of days/shifts lost x 100
Total number of working days/shifts
Frequency rate Number of spells of absence x100
Number of employees
Incidence rate Number of employees having any absence x 100
Number of employees
Bradford is also a model without provenance, whose origins are shrouded in
mystery. Although it is anecdotally said to have been the work of a Bradford
University research team, the University has no precise knowledge of it.
Dr. Alistair Ostell, Senior Lecture in the University's Management Centre,
says, "Despite our most thorough investigations, we have not been able to
identify the people who originated this work. We can only say that it
appears to have been at least 20 and perhaps 30 years ago."
Papers produced by organisations as diverse as ACAS, The Industrial Society,
the Institute of Employment Studies and Income Data Services all make
mention of Bradford but without citing any bibliographic sources for it. And
there appears to be no published research to measure its effectiveness
against other models."
He also researched the answer :
"Bradford s Law
Bradford states that the most significant articles to any given field of
investigation are found within a relatively small group of journal
publications. A few journals publish a high percentage of the articles in
the field; and, there are many journals that publish only a few articles.
(Diodato)
Samuel Clements Bradford (1878-1948) was a practicing librarian and one
of the pioneers in the field of Bibliometrics. In his article, Sources of
Information on Specific Subjects , which was written in 1934 and published
in the British Journal of Engineering, Bradford claimed that 2/3 of journal
articles published each year were being missed by abstracters and indexers.
Bradford proposed that the reason for this failure might be caused by the
way the subject is distributed among the periodicals (Bradford).
After careful observation, Bradford found that most of the papers on a
certain subject were published in a few journals and some articles were
scattered in many borderline journals. Bradford concluded that there existed
an inverse relationship. He split the number of journals into three zones
such that each zone contained a third of the articles.
In studies of applied geophysics and lubrication bibliographies,
Bradford discovered that a third of the articles were found in 9 out of 326
publications, zone 1. Another third of the articles were found in the next
45 journals, zone 2. The last third of the articles were found in the next
225 journals, zone 3. Bradford called the articles in the first zone the
nucleus or core collection and those found in the rest of the journals
were called the scatter collection.
Bradford noticed that the number of articles in zone1 could be
multiplied by 5 to get the number found in zone 2. If the number in zone 2
were also multiplied by 5, the answer would be the number of articles found
in zone 3. Bradford determined that the formula for this relationship was
1:n:n2, where n=5 in this example (Journal).
Bradford s law, sometimes called Bradford s law of scatter, is useful,
not just for writers and bibliographers, but for librarians doing collection
development as well. 1/3 of the literature in a field can be covered in a
small collection of core journals. To cover 2/3 of the literature, multiply
the number of journals in the core by a constant (n) which varies by field.
To have a comprehensive collection, multiply the number of journals in the
core by the square of the constant.
Theorists like Bradford s formula even though several problems and
unanswered questions arose from his data. B.C. Brookes and many others have
worked to refine and clarify Bradford s Law and Bradford is quoted often in
bibliometric studies.
Some of the many Bradford references include:
Bradford analysis, Bradford article cohort, Bradford curve, Bradford
distribution, Bradford data
set, Bradford factor, Bradford graph, Bradford log graph, Bradford
group, Bradford model,
Bradford multiplier, Bradford multiplicator, Bradford nucleus, Bradford
partition, Bradfordian
point of view, Bradfordian viewpoint, and Bradford zone. All of the
above terms are simply
defined in Diodato s Dictionary of Bibliometrics.
References
Bradford, Samuel Clements. Sources of Information on Specific Subjects.
Collection
Management. Vol. 1 (3-4), Fall-Winter 1976-77: p.95-103.
Diodato, Virgil. The Dictionary of Bibliometrics. 1994, New York: Haworth
Press.
Drott, M. Carl. Bradford s Law: Theory, Empiricism and the Gaps Between.
Library Trends,
Summer, 1981: p.41-52.
Journal of American Librarianship. Of Making Many Books There is No
End : Bibliometrics and Libraries. Libraries and Computing Centers.
Issue 9
(1988) N. pag.
White, Howard D. and McCain, Katherine W. Annual Review of Information
Science
and Technology. Volume 24, 1989: p119-173."
I have previously posted the early management reports using Bradford :
"As you are probably aware the Bradford factor is a method of analysing the
frequency of an employee's absence which weights short repetitive absences
to reflect their disruptive affect on production. The basic formula is: S x
S x D. Where S is the number of separate absences in the last 52 weeks and D
is the total numbers of days' absence in the last 52 weeks.
IDS first referred to the Bradford factor or formula in Study 365 published
in July 1986. That publication included a reference to the use of
`Bradford' factor point scores by May & Baker (now Rhone Poulenc Rorer).
Contacts at the company say that this method of calculating absence rates
had been introduced as a result of managers attending a series of seminars
on production management arranged as a part of a Bradford University
management course in the mid-1980s. Controlling absence was one of the
management areas that was covered. However, as you discovered, if you
contact Bradford University's School of Management they know very little
about it and I have never come across any published record of its academic
origins.
Published IDS references include:
IDS Study 365, 'Absence', July 1986, page 5
IDS Study 498, 'Controlling Absence', January 1992,
pages 3/4 (successful use of the formula at Victoria Coach
Station)
IDS Study 556, 'Absence & Sick Pay Policies', June 1994, page 6
A description of the factor also appears in `Measuring and monitoring
absence from work' published by the Institute for Employment Studies in
1995, although its origins are not given."
Hopefully this will put to bed the "Bradford" question for all time, so that
it can stay in the Archive (where in my opinion it belongs - it is too
coarse for use by Occupational Health professionals).
Geoff Helliwell
-----Original Message-----
From: Occ-health is a list open to everyone with an interest in
teaching, learning [mailto:[log in to unmask]]On Behalf Of Amanda
Dowson
Sent: 11 March 2002 15:56
To: [log in to unmask]
Subject: Re: Bradford Scale
Hi this was a discussion from about 1 year ago. There will be info on the
archives Sue. I cant remember the details of it but the origin of the work
was in doubt.
Amanda Dowson
Bradford College
> ----------
> From: Sue Brown[SMTP:[log in to unmask]]
> Reply To: Sue Brown
> Sent: Monday, March 11, 2002 3:53 PM
> To: [log in to unmask]
> Subject: Bradford Scale
>
> Could anyone give me a reference for details of the 'Bradford Scale'
> absence monitoring method
>
> Many thanks
>
> Sue Brown
> Research Associate
> Health and Safety Ergonomics Unit
> Department of Human Sciences
> Loughborough University
> Leicestershire
> LE11 3TU
>
> Tel: 01509 228482
>
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