|The Construct Validity of a Traditional 25m Test of Swimming Competence|
Junge, M.1,3, Blixt, T.2, Stallman, R.K.1,4
A universal definition of the ability to swim has yet to be agreed upon. Some believe that “how far” one swims is the most important criterion. The number of meters is controversial. Some use a traditional definition of from 25m to 200m, often as the only criterion of “can swim”. In fact, this is not the point. A conceptual model emphasizes broader competence. The result of this model is a combined test including more than only dis-tance. This combined test was used as the criterion to test the construct va-lidity of a traditional test. When these two tests were compared they were found to be very different, thus measuring different qualities. Among children already declared able to swim by the traditional test, only 5.7% satisfied the conditions of the conceptual test. It was concluded that the traditional test was not a valid measure of the ability to swim.
Learn to swim programs remain dramatically different in their content and in the manner in which the learner’s progress is evaluated, in other words, by which criteria a child is judged “able to swim”. There is for-tunately, growing agreement among researchers and educators on the importance of a) breath holding, breath control, b) floating, buoyancy control, c) gliding and postural control, and d) stroking and directional control, as well as orientation, balance and rotation (Stallman, et al, 2008).
These are seen as essential, core elements. There remain however, many ideas about how and what a child should learn. The less experi-enced person (school teacher who is not a swimming instructor, par-ent, significant other) is more prone to fall prey to misconceptions. In a recent Scandinavian questionnaire investigation, it was revealed that almost every primary school head master had her/his own definition (Directory of Education, Norway, 2008).There also remains a traditional notion that the number of meters achieved is the only or most important criterion for defining the ability to swim. This is especially true among parents but sadly, remains com-mon also among certain swimming instructors. A common complaint is that “we don’t have enough time”. The result is often a single selected stroke and a pre-determined distance (Directory of Education, Norway, 2008). The notion that some form of all around development is more important than simply a certain number of meters seems to have es-caped closer scrutiny. A number of well known and respected national agencies (e.g. The American Red Cross, The German Life Saving As-sociation, etc.) have long emphasized all-around development as essen-tial in drowning prevention. The concepts of “watermanship” or “aquatic competence” are well known (Sinclair & Henry, 1893, Langendorfer & Bruya 1995). Both Cureton (1943) and the USA Navy (1943), empha-sized that drowning can take many forms, and that these are unpredict-able. Therefore, many solutions (all-around development) are necessary to solve many possible life threatening situations.
When considering the ultimate negative outcome of an aquatic “episode” (death by drowning) it is clear that a variety of skills is required to cope with the wide variety of possible situations in which an unsuspect-ing person might find themselves – in the water. It surely is obvious then that, one stroke or one distance is not sufficient. Unfortunately, some still appear to believe it is. And the discussion goes on, 25m, 100m, 200m? And of course, whatever conclusions one reaches about skills, we also tend to neglect knowledge, attitude and judgment.
The motive for this study was thus to examine the idea that it is not how far but how one swims that really matters. The aim of this study is thus, to examine the construct validity of a 25m test of swimming com-petence by comparing it with a criterion combined test, maintaining the same overall distance on both. It was also assumed that the same results would appear if a different distance had been chosen. For example, that a traditional test of 200m with single stroke is not the same as a 200m combined test with the same pattern as the shorter combined test.
From among 200 primary school children, age 9&10 years, taught in a single school term, 70 succeeded in the local traditional test of negotiating 25m with no other criteria. These 70 were declared “able to swim”, award-ed a pin and the parents were notified that their child could swim. These children (N=70) constituted the subjects of this study. By performing a second test, within 3 days of the first, they served as their own controls.
The criterion “combined test” consisted of: a) jump or dive into deep water (3m), level off, b) swim 12.5 m in the prone position c) turn 180 degrees, d) roll over e) rest for 30 sec with minimal movement, f) swim back to the starting point in the supine position. Diving was awarded two points, jump one point and 0 for those who refused both jump and dive. Each of the other elements was awarded two points. The maximum possible score was thus 12 points. The total distance was the same for both tests but the criterion test was obviously more comprehensive, in-cluded a more balanced skill profile.
The children were motivated by being offered a second, new award. No mention was made of the second test being a test of swimming abil-ity nor was it implied that the first test was anything other than what they had believed it to be. To any direct question, the second test was simply referred to as a “new” test, and new award; swim or swim better.
The children were tested by their own teacher to avoid bias by alter-ing the atmosphere. The observers who evaluated the performance were known to the children. The children were tested four at a time and each of two observers was assigned to two children. The same observers evalu-ated all of the subjects. Pilot testing was conducted to train the observers. Discussions were held to ensure that both observers used the same criteria. A head instructor coordinated all evaluation and made the final decision in any case not obvious in its outcome. Each element was scored and the total score was recorded. The results were tabulated by frequency distribu-tion and both the number and percent of subjects succeeding on each element was recorded. The total scores were also recorded.
The criterion test was the result of a construct, i.e. a conceptual con-struction based on the logical arguments cited above. If these two tests gave similar results, the traditional test would be accepted as having construct validity. If the two tests differed they would be considered to measure different qualities and the traditional test would be considered not to have construct validity.
Table 1 shows the results by element. The results clearly show that all but the one element reproduced also on the first test, were not mastered by many of the children.
As would be expected, 100% of the children who had already swum 25m on the front, succeeded in swimming 12.5m on the front. How-ever from that point on, fewer managed the other elements. Twenty six percent refused to either jump or dive into deep water, asking to start in the water. Ten percent did not manage to change direction. Forty three percent were unable to roll over. Forty nine percent were unable to swim on the back. And lowest of all, only 5.7% managed to stop and rest, even for only 30 seconds.
The range of total scores was from 4 to 12. Only four of these pupils scored 11 or 12 points, i.e. by the criterion test, could swim.
The real issues here are, how do we evaluate whether a child can swim or not, and can a simple distance test serve the need to evaluate. To return to the idea that it is how one swims rather than how far, we must forsake traditional ideas of any given distance. Some insist on 25m, some on 200m, others are somewhere in between. It can be remembered that the Scouting movement has long operated with a 200yd (ca 180m) minimum before permitting boating activities (Scout Handbook, 1956). Several national life saving organizations also have a tradition of focus-ing on 200m or 200 yds. In some cases, no other criteria are used. Can it be that one who can swim 200m but not 201m, can swim? How safe is this person? How are they prepared for the many possible scenarios one might be victim to in an involuntary submersion?
The results of this study show clearly that the two tests considered, measure different qualities. Being able to swim 25m non-stop on the front does not automatically give one the ability to swim in the back, turn, roll over, stop and rest or jump or dive into the water. (if an emer-gency required one to swim on the back or to stop and rest (gather ones wits, catch the breath, settle down, re-orient oneself) as it might well do, these subjects would be in serious difficulty. They are clearly, not as safe as they might have been if they had mastered the criterion test. Consider the statistic cited by Golden and Tipton (2002), that > 40% of drownings in the UK happen within 3m of safety. The logically matching scenario would require the victim to turn around and make their way back to safety. Cold shock also first described clearly by these same authors, operating within seconds of submersion and dramatically raising the respiration rate, reducing air exchange and raising the HR, requires clearly the quality of being able to stop, rest, take stock, catch the breath, etc. It remains a mystery to us that the ability to stop and rest is so often ignored or underestimated.
To accommodate the desire to keep some semblance of distance as a useful skill (attitude?), it is only logical to suggest that the criterion combined test examined in this study, can easily be expanded to greater distance while retaining the same pattern. An example might be a total of 100m (50 + 50) with a 60 sec. rest and perhaps a more demanding way to fall into the water, or 200m (100 + 100) with a 3 min rest. Clothing could (and should) be added to increase the challenge. Stallman, et al. (2008) introduced the idea that “Can Swim” is not a sharp demarcation from “Cannot Swim” but rather a zone in which we can describe can swim at a minimal level and progressively at higher levels. Can and Can Better. See Fig 1.
In Northern Europe there exists a certain feeling about swimming on the back, insisting for example that in a 200m test, only 50 need be on the back. This is to denigrate the value of a life preserving skill. And often no other criteria are used. The combined test approach presented here as a construct, is a balanced one.
To focus on any distance is to avoid the issue. It is not a question of how far or which stroke. The child who is relaxed in the water and uses their natural buoyancy, is able to control breathing, is able to stop and rest, is safer at 25m than the child who can swim 100m but does so only non-stop and with great effort. The first named child can swim 25, stop and rest, swim 25 more, etc and soon accumulates a greater distance than her/his counterpart. Those who focus on distance only, see only the result and lose sight of the process. Here the reader is reminded that a common attitude among less experienced instructors is that technique is not important, most children never become competitive swimmers. The real issue however is that economy of effort is often a matter of life and death. Technique in fact, when we consider saving energy by more efficient movement, not overcoming the powers of nature but working in harmony with them, is the most valuable of survival skills.
There can be little doubt that the ability to swim 200m indoors in a warm quiet pool, is no guarantee that one can swim the same distance outdoors, in colder and restless, open water, and perhaps fully clothed. But at what ever distance one arrests the learner’s progress, in a labora-tory slice of life to be examined under the microscope, the pattern of versatility should be retained. Each element would then be increased to a higher level of challenge.
The distance test of 25m, with no other criteria, measures different qual-ities than the slightly more comprehensive combined criterion test. If we accept the construct validity of the criterion test, the traditional test is necessarily judged not to have construct validity.
Cureton, T.K. (1943). Warfare Aquatics, Champaign, IL, Stipes Pub.
Directory of Education, Ministry of Education, Norway (2008). The Teaching of Swimming and Life Saving; Support materials for teachers and instructors in the primary school. Oslo, Norway
Golden, F. and Tipton, M. (2002). The Essentials of Sea Survival, Cham-paign, IL. Human Kinetics
Higgins J., et al. (1943). Swimming and Diving. The United States Navy. United States naval Institute, Annapolis, MD
Hines, F. (ed) (1978). The Scout Handbook, Boy Scouts of America, N.Y.
Hurt, H.W. (ed) (1910). Handbook for Boys, Boy Scouts of America, N.Y.
Langendorfer, S.J. and Bruya, L.D. (1995). Aquatic readiness. Cham-paign, IL, Human Kinetics
Sinclair A. and Henry W. (1893). Swimming, London, Longmans
Stallman R.K., Junge M., Blixt T., (2008). The teaching of swimming based on a model derived from the causes of drowning. Int J of Aquatic Research and Educ, 2(4), 372-382