Learn to ski the easy way
With the short ski method
New Study Confirms:
SHORT SKI METHOD STILL SUPERIOR TO STANDARD TEACHING METHOD FOR ADULT
BEGINNERS
Ken Lawler
D-85521
Ottobrunn
The controlled
study presented here, brings new evidence about the superiority of the
Short-Ski Method or Graduated Length Method (GLM) over the standard American
Teaching System (ATS). The study was performed under the following scientific
aspects:
· A
control group and an experimental group were utilized.
· All test
criteria were objectively measurable.
·
Measurements were taken both at the beginning of the ski course and at
the end of the ski course. Each skier's relative improvement within the
combined groups was recorded. In this way the difference between the two
methods could be isolated from the difference between the skiers' abilities .
· The statistical significance level was established.
BACKGROUND
The short-ski
method or Graduated Length Method (GLM) was developed by Clif
Taylor in Vermont in the 1960's. The strategy is to start on very short skis
(65-80cm) and use the parallel turn from the very beginning. The skier
progresses to gradually longer skis as he improves. The method employs very
little technique explanation and is characterized by a great deal of action and
self discovery. GLM was very popular in the United
States especially at Killington, Aspen Highlands and anywhere,
that Taylor went to promote his method. Short Ski methods were also
developed in Austria by Karl Koller, in France (Ski Evolutif) by Pierre Gruneberg
& Robert Blanc and in Germany (Ansteigenden Ski Längen--ASL) by Martin Puchtler.
Since the introduction of Kneissl's 63 cm Big Foot several authors have proposed
beginner teaching methods using it. Kurt Schock was
probably the first. One major difference between the Big Foot Method and GLM is the method used to familiarize the
learner to longer skis. For the transition phase the Big Foot Method uses a Big
Foot on one leg and a full length ski on the other.
This study was
carried out using the method proposed by Puchtler ^{9} . The Skischule Nordbayern (Since Puchtler's
death in 1995 under the direction of Karlheinz
Fischer) still uses this method successfully. I learned to ski at this ski
school and am currently a short-ski ski instructor there. Although many ski
schools offer Big Foot Courses, there
are currently only 5 Ski Schools in the world offering a true graduated length
program to beginners: Skischule Nordbayern in
Bischofsgrün, Skischule Montana
in Grafrath, Ecole de Ski
International in Alp d'Huez, Ecole de Ski Francaise and Arc Aventures
in Les Arcs.
There have been
6 controlled studies ^{1,2,3,4,5,12,13} which
compare the short-ski method with the standard ski teaching method. All studies
except one indicate, that the short-ski method is superior to the standard
method. None of these six studies presented statistical significance. Sturm^{1
}and Pfeiffer^{2}/Fry^{4 }attempted to subjectively
establish innate (before the study) similarities and differences between
short-ski participants and control group participants. None of the studies
included tests both before and after the instruction period.
TESTING
PROCEDURE
To justly
compare the two methods, measurements were made both before and after
the instruction period. Skills, that will be measured afterwards, are not yet
present before ski instruction takes place. For this reason two different sets
of skills must be measured. The Pre-Test measures coordination and courage. The
Post-Test, a composite test, measures speed and control. Because these two
tests measure two different things on two different scales, it is necessary to
find a common unit of measure. The ranks of the the
raw scores on these tests serve this purpose.
In addition to
the pre test and final test, observations were made
to estimate success on the first day.
Pre-Test
A
pre-instruction test must measure skills, which are possible after only 90
minutes on skis. This test must measure coordination as well as courage.
Gliding straight down the fall line on a very slight incline, stepping back and
forth over a rope or marked line (as described in the DSLV SkiLehrplan
^{7 p. 109} ) is an objective test for measuring these two facors.
Success on
first day
Perhaps the
most important measure of a ski teaching method is the taste of success on the first
day. Four objective measurements for the first day are:
1. Distance
skied in meters
2. Vertical
meters skied
3. Number of
direction changes executed
4. Number of
falls per 10 direction changes
Post-Test or
Final Test
Two elements
in skiing summarize the goals of most skiers: speed and control.
These two elements are necessary for most skiers to have fun. The following
events provide an objective means of testing these elements:
1. Slalom
race on a green slope. (measuring speed and control)
2. Free Run
Race on a green slope. (measuring speed)
3. Number of direction changes
over a short stretch of blue slope. (measuring
control)
A direction change is defined as both skis turning across the fall line and
changing edges.
Each
participant's ranks in these three events are added together to yield the Sum
of Post-Ranks (column Sum of Post Ranks
in Table 2). The lower scores are better.
Technique is
not an end in itself, but rather a means to reach the two more important goals:
speed and control. Modern Ski Teaching methodology even
discourages teaching a normed ski technique. Technique is also a very
subjective matter and so a technique test would lend itself to manipulation or
claims of manipulation. Speed and control, on the other hand are
simple to measure . For these reasons we choose not to
use a subjective judgment of technique as part of the Post-Test.
NARRATIVE OF THE STUDY
The AFRC Ski
School at Garmisch is an ideal environment for such a study because of its
consistent high volume of full-week guests and the high degree of
professionalism demonstrated by its instructors. The week I was there in
February 1997, there were 350 skiweekers. The Ski School is a Professional Ski Instructors
of America (PSIA) Ski School and hosts PSIA Certification Examinations each
year. The Ski School uses the standard American Teaching System as presented in
the PSIA literature ^{10} . The Ski School
Director, Shred (Leigh Plowman, a PSIA examiner) is very open and helpful and
was interested in this study. The instructors are well trained, having a
minimum of 12 days internal training. By mid February
even the rookie instructors have 50 days of practical experience. At the end of
each Skiweek
the ski school hosts a final Slalom race. This race provided part of the composite
Post-Test as described below.
On
registration day first-time skiers were asked if they wanted to participate in
the study by learning to ski with the short-ski method. 12 out of the first 15
candidates chose to do so. The remaining 17 adult first-timers were assigned to
the control group. The two groups were very similar. The ages ranged from 17 to
44. There were no apparent disabilities. None of the the
participants were particularly athletic. Most had office jobs.
All first-timers
were fitted out normally in the AFRC ski rental shop with ski boots and
standard length beginner skis (160 cm). On the first morning the short-ski
group as well as the control group were taught using their standard length
beginner skis and the standard teaching method.
The
instructors for the control group were BSam (Brian Samway) and Squirrel (Carl Swanback).
BSam is a rookie ski instructor with a level 1 PSIA
Certification. At the time of the study he had about 50 days of practical
experience. Squirrel has many years of experience as an instructor and as a Ski
School director. He has a level 2 PSIA Certification. The short-ski group was
taught by myself and I have a Level 1 German Ski Instructors Association (DSLV)
Certification and many years of ski teaching experience.
After 90
minutes of instruction the Pre-Test was performed. The short ski group was
still on 160 cm skis. A 25 meter rope was stretched out along the fall line on
a slight incline. The participants were instructed to ski along the rope
stepping back and forth across the rope as many times as possible. A step is
counted, if it is made first with one foot then the other and if each ski lifts
off the ground. The number of clean steps across the rope provided the raw
score for the Pre-Test. (column Pre-Test Score in Table 2). (column Pre-Test Score
in Table 2). The control group was slightly better than the short-ski group at
this stage. See the collation of the two groups in the left half of
illustration 2.
At lunch time
short skis (70-90cm) were fitted to the short-ski-participants' boots. They
were taught using the principles set out in Puchtler ^{9}
and Lawler ^{8}. BSam and Squirrel continued
to instruct the control group using ATS. The measurements for the first
afternoon were made by two observers and their results are shown in the
following table:
First Day Results:
on Average per Person: |
Control Group |
Short-ski group |
Meters skied |
383 |
490 |
Vertical Meters skied |
36 |
54 |
Number of Direction changes |
22 |
160 |
Falls per 10 direction changes |
0,25 |
0,12 |
Table 1 Success on first afternoon
The short-ski
participants were given longer skis each day. On the fifth and final day the skis' lengths were
140-160cm. (predominantly
150cm).
The skis used for
the short-ski group were:
70cm-120cm Sawed-off skis out of the trash heap.
130cm Kästle Firn Extreme and Hagan Tour Extreme
135cm-140cm Various
Learning skis bought used from American Skirental
shops-
150cm-160cm Youth skis with
Adult Bindings from the AFRC Ski Rental
On day two the
control group was reshuffled. The better skiers went to Squirrel's group and
the weaker skiers went to Bsam's group. One short-ski
participant quit the ski course as did several from the control group. On the
third day Squirrel's group had 6 and Bsam's group 8
as opposed to 11 in the short-ski group. This finer differentiation of
abilities as well as the smaller group size were an advantage factor for the
control group.
From the
original groups 9 out of 12 of the short-ski group and 6 out of 17 of the
control group were present for the entire Post-Test on the fifth and final day.
The Post-Test was carried out as described above. The finishing places in the
three events were summed to yield the Post-Test Results (column labeled Sum of
Post-Ranks in Table 2). The graphical representation of those results is shown
in the right half of illustration 2. The Pre-Test Order reflects the ranks of
the steps taken over the rope in the Pre-Test described above. The Post-Test
order represents the ranks of the sums of the results of all three events
described above. Notice that the short-ski group was slightly behind in the
Pre-Test, but was clearly superior after the two methods of instruction had
been used in the Post-Test. In the slalom race the first two women's places and
the first two men's places were from the short-ski group. The number-of-turns
test was won by a latecomer (advanced beginner) in the control group who had
not been present for
the Pre-Test. The next 6 places were from the short-ski group. In
the free run race the first 6 places were from the short-ski group. The
complete results are listed in Table 2.
Table 2 Complete Results
GRAPHICAL REPRESENTATION OF
THE RESULTS
Illustration
2 Rank order before and after the test period
STATISTICAL ANALYSIS OF THE
RESULTS
Hypothesis
tests test whether two treatments produce different results. Based on the
results of the sample or test, the significance level indicates the probability
that a hypothesis is true. (as opposed to random
events causing any difference in results.) (See Conover ^{6 p. 76}.)The
testing procedure must decide whether the results of the two treatments are
different enough to be able to assume that the 2 treatments always produce
different results from one another.
The null
hypothesis H_{0} states the equality of the two treatments which is to
be disproved. The alternative hypothesis H_{1} states that there is a
significant diffence between the two treatments. The
experimental layout here is the randomized two sample model. For this model
there are two distribution free significance tests. Each of these tests is
valid with reference to its two hypotheses.
MANN-WHITNEY
TEST OF STATISTICAL SIGNIFICANCE
H_{0} : The middle short-ski
participant improves his overall ranking less than or equal to the middle
control group participant during the test period .
H_{1} :The middle short-ski participant improves his overall
ranking more than the middle control group participant during the test period .
Note that the
term "improved more" is used rather than "skis better". The
evaluation "skis better" would include the
effect of the skiers inate ability as well as the
effect fo the teaching method.
The ranks of
the three Post-Test Events are added together for each participant. These sums
are replaced by their respective ranks (column labeled End Rank in Table 2).
From each rank subtract the corresponding rank from the Pre-Test yielding the
rank difference for each participant (column labeled Rank Dif
in Table 2). The largest negative difference shows the most improvement as a
result of instruction.
From this
comparison we can conclude that the short-ski method is superior with a
statistical significance of approximately 0.998. This means, that the
probability of this result or a stronger result under conditions of the null
Hypothesis (no difference in the effectiveness of the two teaching methods) is
approximately 0.002 (2 chances in a thousand).
BINOMIAL TEST
OF STATISTICAL SIGNIFICANCE
We could
reword the hypotheses as follows:
H_{0} : The Probability is less than or equal to ½, that a short-ski
participant improves his rank within the long ski group.
H_{1}:The Probability is greater than
½, that a short-ski participant mproves his rank
within the long ski group.
In this case
we can use the binomial test to test the significance of the data.
Since each one
of the 9 short-ski participants improved his ranking among the control group,
the binomial test indicates that this result has a statistical significance of
0.998. This means that this result would occur in only two out of a thousand
cases if the underlying probability were less than or equal to ½. The
underlying probability is the probability that a short-ski participant would outimprove the
members of the control group).
ANALYSIS OF THE DROP-OUT RATE DIFFERENCE WITH A CONFIDENCE
INTERVAL
The high signifikanz level of the
results of the hypothesis tests applies to those who held out until the end of
the course and the final test. 65% of the control group participants (long ski)
was incapable or too embarrased to take part to the
Final test or quit the skiing course entirely. In comparison only 25% of the short ski
participants fell into this category. To what degree can this relationship (40
percentage points difference) be applied to the parent
population? One can calculate an area around the observed difference, in which
one would expect to find the difference in further equivalent experiments with,
say a 0.95 probability. This area is described as a 95% confidence interval. ( see Conover ^{6 S . 99}. ):
The number of the participants of the respective group which
would be missing at the final test has a binomial distribution (see Conover ^{6
S. 81}). The parameter p of this distribution control groupe . Assuming that these
two proportions are independent from one another, the difference has a Bivariat binomial distribution.
Result:
The 95% Konfidenzintervall lies in
the area of 7% to 70%. Ths means: We expect that the
portion of the conntrol group (long ski) which is
absent at the final test to lie between 7% and 70% more than the corresponding
portion at the short ski group in 95% of further equivalent experiments
CONCLUSION
Statistically
the results show that it is highly unlikely that such a strong difference in
the measurements could have resulted from chance. With these facts it can safely
be asserted that the short-ski method is still superior to the standard
teaching method when teaching adult beginners to ski. Specifically beginners
learn to ski more controlled as well as faster than they would with the
standard teaching method. In addition the short ski method produces less ski
school dropouts than the long ski method.
LITERATURE
^{1} Ralf Sturm; Vergleich zweier Skilehrmethoden; Diplomarbeit,
Friedreich-Alexander-Universität Erlangen-Nürnberg, Institut für
Sportwissenschaft, Professor E. Hecht; 1992
^{2} Karl Pfeiffer; Learning to Ski by the Graduated Length Method ;Ski Magazine (USA); November 1966
^{3} Art Furrer; Graduation Day for Graduated Length; Ski
Magazine (USA); January 1968
^{4} John Fry; Teaching
Systems Compared; Ski Magazine (USA); November 1966
^{5} Friedl List; Mini Ski Rettung der Hoffnungslosen? ; Ski Magazine(BRD); November
1967
^{6.} W.J. Conover
'Practical Nonparameteric Statistics' John Wiley
& Sons, Inc. 1971.
^{7} Erhart Gattermann et. al.;DSLV Skilehrplan 1; BLV; 1981
^{8} Erhart Gattermann et. al.; DSLV Skilehrplan Band 1; BLV; 1994
^{9} Ken Lawler; Teaching
Adult Beginners to Ski; Selbstdruck; 1996
^{10} Heinz Maegerlein,
Friedl List, Martin Puchtler; Neuer Schwung auf kurzem Ski; BLV; 1967
^{11} Max Lundberg; Alpine Skiing; PSIA; 1993
^{12} Horst Üeberhorst,
Walter Kuchler; Vom
Kurzski zum Normalski; Lehrhilfen für die
Leibeserziehung; 1/69
^{13} Harald Kiedaisch;
Alles redet über den Kurzski;
Lehrhilfen für die Leibeserziehung; 1/69