13 MAY 1955, Page 13

Absence-Proneness

THE word 'prone' used to mean 'lying face downwards,' just as 'supine! meant `lying face upwards.' (Why is there no similarly concise Latin-based word for the sideways or semi-hedgehog posture of repose preferred, after all, by most people? Was this form of comfort unknown to the ancients? But we wander from the point.) Today this primary meaning has practically disappeared; 'prone' has become hardly more than a suffix. One is accident-prone, sickness- prone, absence-prone, possibly other-things-prone as well; the term is simply a useful shorthand for that state of affairs in which the victim exclaims, 'This is the sort of thing that always happens to me!'

Such exclamations are not, as a rule, uttered with strict scientific caution. Yet proneness, it appears, is or ought to be scientifically measurable. Take, for instance, absence-prone- , ness; the propensity not to turn up for work. In a recent statistical inquiry* two highly-qualified observers of this human and social phenomenon offer the following lapidary definition : 'We regard proneness as being measured by the product moment correlation coefficient existing between absences occurring to a group in successive non-overlapping periods of exposure, irrespective of the specific type of under- lying bivariate distribution.' This generalisation applies (the reader will be reassured to know) whether the absentees con- cerned are AWP or AWOP. (AWP and AWOP are not, it should be explained, exclamations of dismay lifted from the balloons of comic strips nor names of outer-planetary char- acters in science fiction. They signify respectively Absence With Permission and Absence With Out Permission. The rubric AWP Sick- is self-explanatory' without being onomatopoeic.) where m is the average number of absences per person per week, k the number of weeks per exposure period, and p (take a deep breath) is 'an invariant parameter. estimated . . . by the method of moments as ka2/(72—kin'. Make a graph of this formula—a simple task— and plot against it the actual per- formance of the individuals concerned, and the little men who weren't there, and who are unlikely to be there next year, will stand out with startling clarity—or so one would think. wouldn't one? But no. Some useful aggregate results can be calculated from the observed data, such as that, out of a group identified in period 1 as having Q or more absences, a deter- minate proportion will have Q or more absences in period 2; and that if the whole of this group are submitted to 'remedial treatment' the proportion of cases in which that treatment is necessary will also be determinate. For any given individual, however, uncertainty remains. Much more calculation is needed : 'A longitudinal time-study of personal records is required, estimating the individual's parameter ( A) defined as the mean number of absences per person per unit of time, and showing the variations in his record in successive units of time in the form of a control chart.'

It is not enough, that is, to note that X had a Monday head ten weeks out of twelve in period 1 and ten weeks out of twelve again in period 2; a case, in the author's words, 'with Q or more absences in the first period associated with Q or more absences in the next.' For one thing, Q is necessarily arbitrary; the allowable maximum of Blue Mondays is not a fixed fact of nature. For another thing, in periods 3 and 4 X may show up in quite a different light, his claim to invidious attention dis- appearing while that pf Y, an exemplary timekeeper in periods 1 and 2, conversely becomes urgent. Pure chance, the inscrut- able and capricious Fates which flatten a man's bicycle tyres or stop his watch, afflict him with precipitately-arriving twins or a burst water-cistern, guide his foot on to a banana skin or his appetite towards a dubious piece of fish, or bring his mother- in-law to stay to the detriment of his temperance, may be as much to blame as those 'personal and environmental factors' to which remedial treatment is appropriate; a Methuselah's lifetime would hardly be long enough for the perfect cancella- tion of good and bad luck—and the imagination falters at a composite index, complete with invariant parameters, of puncture-proneness, twin-proneness, and proneness to the consumption of deleterious fish.

Prediction, like remedy, must in fact continue to work to a widish margin of error. It is something, however, to have the principles laid down, the procedure of inquiry made clear, the margin itself defined. Or it ought to be something. When every personnel manager, foreman or shop steward can juggle with univariate negative binomial distributions and invariant parameters it undoubtedly will be something. Meanwhile, Mrs.

Mopp has just telephoned for the fourth time in a fortnight to say that for family reasons she won't be coming in today. (The telephone call may be taken as shifting her, morally, from class AWOP to class AWP.) Questions : How many times is she likely to telephone in the next fortnight? Plotted against the formula embodying the standard observed behaviour of Mesdames Mopp, does this record indicate absence-proneness?

If so, is this proneness person-centred or environment-centred? And what remedial measures are appropriate? 'The elimination of absence-offenders . . . would have little beneficial effect . . .

if they were replaced by newcomers whose record turned out to be equally bad.' How true. Mrs. Mopp's successor, if any, probably wouldn't even telephone. Before her absence-prone- ness, objectively or subjectively determined, the higher mathe- matics are lamentably unhelpful. There is only one attitude to be adopted : the supine.