How to remove observer bias from grid based observations

[ChenaySimms]

Hi all

I have old animal sightings data that I want to analyse for distribution, frequency and landscape utilization. However the data was captured using a grid system where all animals seen within a specific grid cell get assigned the coordinate of the bottom left corner of the cell.

The area is fairly mountainous and there seems to be a strong bias towards grid cells with roads through them. 

Is there a way to quantify and or remove this bias?

Any suggestions would be welcome.

Regards

Chenay

[BenLeslie1]

I can't answer the question but you need to think carfully about the bias and what is causing it.  Is it because there are more observers on the road or are the animals attracted to the roads, maybe by road-kill or litter.  Do shubs/hedges/farms/houses line the roads are these a habitat for the animals?  Do roads run through areas that are reletively flat and does this make them more habitable?

If you don't have these answers you may just have to accept that the data isn't good enough to tell you what you want.  If you do have these answers you may need to employ a proper statistician to help you understand the data.

[ChenaySimms]

Thanks for your comments, I will definitely look further into that aspect of it 🙂

I have a statistician helping with the analysis, I was just hoping that this data would lend itself to a more spatially based analysis.