(b) The relation between wings sent in by a hunter and the 
number of ducks killed by the same hunter is not directly 
measurable from the data at hand. There apparently is a 
relationship between the kill reported one year and the 
number of wings sent the next (Table 6); this suggests 
that there may be a relationship within the same year. 
(c) The relationship in a area between the average number of 
ducks killed per respondent and the average number killed 
by all hunters cannot be examined with available data. The 
non-response fraction in the mail survey prevents such a 
direct measurement. 
Beyond their use in calculation, the weighting factors shown 
in Table 5 indicated the extent and direction the numbers of wings 
collected from each State must be adjusted in order to obtain a 
properly weighted total. Thus, for Ohio, the weighting factor of 
0-52 indicates that Ohio was relatively oversampled, since the 
original numbers must be reduced by almost one-half before the 
Ohio data can be combined with the weighted totals from other States. 
RESPONSE RATES 
Response Rates from Individual States 
Letters requesting wings were mailed to 8,076 hunters, but 
the Post Office Department was unable to deliver 79 of the letters. 
Thus, 7,997 hunters received letters. The accompanying wing 
envelopes totaled 88,661. 
Response rates were calculated for the four States (Arkansas, 
Illinois, Michigan, and Wisconsin) where numbers to identify 
individual hunters had been added to the wing envelopes. The response 
rate for these four States varied from 21.9 to 24.2 per cent (Table 6). 
These rates were close to the 25.2 per cent response rate of the 666 
hunters included in the Minnesota Pilot Study in 1958. As discussed 
later, however, Table 6 shows also that response rates of the more 
successful hunters tended to be higher than those of the less successfule 
Therefore, different proportions of hunters in the different success 
categories could change the over-all response ratee The response rate 
in Illinois may have been increased by the follow-up letter (see page 11). 
Response rates for other States could not be calculated directly because 
envelopes did not have numbers that identified individual hunterse A 
count of hunters' names written on the envelopes received from certain 
States, however, indicated that the response rate was much lower 
(14.3-10.3 per cent) in Indiana, Kentucky, Louisiana, Mississippi, and 
Tennesseeo In the 1960 wing collection, all hunters will be assigned 
numbers so that response rates can be computed. 
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