EXPLANATION OF INDEX VALUES ASSIGNED EACH STUNT

The percentage of students,who were successful in reaching the required
standard in each stunt after the practice period, was computed. These percentages
were then expressed as differences from the avcrage, the stunt successfully done
by 50% of students. So the Forward Roll (;:1) would represent a -49% difference
from the average (99-50): and the Chest Roll (3730) would have g difference value
of 40 (50-10). On the assumption of a normal distribution; these difference values
are expressed in terms of standard deviations from the mean (the 50%, point), using
the proper statistical table. “Standard Deviation" values of each stunt are then
referred to a scale in which <3 stondard deviations (0 on our scale) represents the
easiest possible stunt, and #3 standard deviations (6 on our senle) represents the
hardest possible stunte

The difficulty values of the stunts for which we have figures range from
287 to 4e756

Since these indexes are in terms of standard distances on o linear scale they
can be directly compared. Item 729 is thus almost oxactly twice as difficult as
items 38 and #9, Item 733 is seven times as hard to learn as stunt jl. Item 76
is as much harder than ;'5 as 7-25 is harder than ;246

Pupils learning the various stunts should be given ercdit, therefore, in pro-
portion to these standard difficulties of cach performance.

DISTRIBUTION OF STUDENTS BY GROUPS

 

 

 

 

 

H our Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Goupt
I > +) 14 13 7 3 0 5
il c 5 14 iz 8 7 0 3
III 2 5 14 19 2 4, 2 0
IV 3 & 19 14 9 1 0 1
VI 4. 1 15 8 6 +) 0 0
VII 2. 5 12 17 5 5 0 0

 

 

 

 

 

16 20 88 83 o7 21 2 7