User: | Open Learning Faculty Member:
After trying out the sample methods tutorial I was able to gain some insight in to the pros and cons of each sample method. Haphazard sampling was the fastest method, but as I could see when comparing accuracy it was low preforming in that area. This makes sense since I chose my sections based on areas with high tree density. The one that took the longest was the systematic survey this seems accurate since I chose to check every 7th grid. This created extra work and more grids were surveyed then the others types.
The percent error of the two most common trees based on the three sampling strategies the random sampling was the most accurate, for the two most common trees, and the haphazard was the least accurate.As for the least populous trees only the random sampling actually accounted for both trees in the survey. The haphazard sample picked up neither, and systemic survey only found one of the two.
From the result over view it appears that the random sample survey did a more accurate job that the other two types. In terms of hours spent on surveys it was in the middle. This is important to consider when I am looking at collecting my data for my project. More time invested in to systematic survey with a increased sample size my not give you the most accurate results. On the other hand random samples fall to chance and a large are of the survey grid could be missed. This is something to consider when looking at the randomly chosen quadrants and collecting your data.
Haphazard while convenient and more efficient and economical has to be critiqued for a large bias in selecting quadrants or zones for surveying, or risk an invalid data set and wasted time.
