Hello everyone!
At last I’m able to post a summary of my research/findings. I tried using an inverted pyramid format and include simple explanations for those that don’t want all the details as well as some numbers for those who love statistics, however if you want a more/less technical post to clarify some things, just let me know.
Main Hypotheses
The main purpose of the study was to test whether experience (measured in flight time) had any effect on risk perception. To do this a correlation test was used (Spearman's).
Total flight time’s effect on the mean risk perception score of all 17 items had a correlation score of -.258. It’s a relatively weak relationship as far as correlations go, but simply put the more hours a pilot has, the lower he rates risk. The result was statistically significant at the p<0.01 level, which means the odds of this result occurring purely do to chance are very remote.
Recency was also explored by using the flight time in the last 30 and 90 days. For the last 30 days none of the results were statistically significant, I suspect partially due to a smaller sample compared to the other two (quite a number of pilots had not flown at all in the past 30 days).
The relationship between flight time in the last 90 days and mean risk perception was however statistically significant (p=0.033), and the correlation was similarly negative but weaker than for total flight time (-0.165).
All of that means that risk perception isn’t something that varies very remarkably with experience, and, from my research at least, it tends to go down even if ever so slightly as a pilot flies more.
However, when one examines FAA/NTSB data for fatal accidents, there does seem to be proof more experienced pilots crash less. The most ‘popular’ book along these lines is Paul Craig’s ‘Killing Zone’, but recently William Knecht modified a bit the approach by using accident rates rather than frequencies. His paper is here:
https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2010s/media/201503.pdf but more significantly, he has an updated ‘camel hump’ curve on page 16 which illustrates that the ‘killing zone’ is larger than previously assumed.
Age, Main Type of Flying activity, and Personality traits
A number of other collected demographic factors were also tested. Age did not have any significant effect, and neither did main type of flying activity. Since there was some data linking automobile accidents to Extraversion and Openness to Experience, (the more extraverted and open to experience a driver is, the more he is involved in fatal accidents), I thought it would be interesting to also include a short personality test to measure these two scales, however the results also turned out to be statistically insignificant (more extraverted individuals didn’t have significantly higher risk perception scores for instance).
Highest Licence held
One group where there was some statistical significance was by highest licence/rating held. The One-Way ANOVA score for the effect of certification level on the mean risk perception score was F(6,160)= 3.032, p=.008.
The major limitation of this graph is that some groups have rather small numbers, so generalizations have to be made with caution.
Additionally, I noted all your comments about the scale’s difficulty (the anchor set too high, hard time in rating on a 1-100 scale). One of this study’s recommendations is a new scale since this would help validate this scale and the whole risk perception construct in general. The tricky bit is it’s very hard to measure perception using means other than a self-report inventory.
Super Summary
Regardless, if I can sum it up in one sentence, it would be this: Experience does seem to be a protective factor against accidents, but why this is so, and the exact mechanism through which it works to do so is: (i) very unclear and (ii) probably not straightforward.
If you have any questions/comments please let me know, and additionally, I plan to post the whole PDF here when it becomes publically available on my University’s website.
Additional Info:
The questions ranked from most dangerous to least:
https://www.dropbox.com/s/8uyst8kf6ul4umk/Questions%20ranked.docx?dl=0
Craig's book:
http://www.amazon.com/Killing-Zone-...ng+Zone,+Second+Edition:+How+&+Why+Pilots+Die
-Charles