It can be kind of liberating to get out into the field early in a new research project. Without a sampling strategy and data collection plan though, you are probably wasting your limited research money 😦
Fortunately, there are heaps of ways to get some perspective on, and put together a plan for, your study site(s) before your feet pound the trail!
Starting to plan your fieldwork takes a little more than just looking at some maps though – even if they are interactive digital ones! If you haven’t looked at any maps yet (digital or otherwise), the Exploring Your Study Area page in the SAL Portal has links to global, regional and local spatial data viewing tools that can help you to get started.
From here, you need to consider a couple of things:
What do you need to collect when you are out there?
This might seem pretty obvious, but it isn’t always. What you need is entirely dependent on what your research is about, the critical thing to remember is that you can never go back to a sample site once you have left it. Even if you can get back to the same location, time and other factors may have changed things in ways that effect collecting additional samples and adding them seamlessly to your original set. If you are not sure whether you need to collect a particular variable or information about a factor or feature, speak to your supervisor in advance.
It sometimes helps to draw up a table, particularly if you plan to later map your fieldwork results using GIS, and think about the columns in the table as the attributes that you want to use in your analysis. Keep one piece of information per cell and think carefully about how useful a ‘notes’ column really is…
What are the things you would make ‘notes’ about?
Do they deserve their own column so that you collect that information consistently for every site/sample?
Are your samples best represented as points, lines, or polygons?
If they are not points, what are the start/end or boundary conditions that define a ‘sample’ and a ‘site’?
If you are taking a GPS:
What coordinate system/ projection/datum should you be collecting your points in?
Are you going to write them down in your field notes or create a waypoint or feature on the GPS unit?
Do you know how to download the data from that type of unit?
Would it be helpful to speak to one of the SAL Tech Staff in advance?
(Tip: If you don’t know what system the coordinate pairs you wrote down are in, someone who wasn’t there is going to be guessing too!)
What Sampling Strategy will you use?
Planning a sampling strategy in advance isn’t just for projects where you can’t easily see what you are collecting. Standing the centre of an area of interest and thinking “that looks OK” is not a form of random sampling. Humans are pattern creation/recognition engines and that spot that felt “picked at random” probably wasn’t. Oregon State has a webpage on Simple random sampling in the field (PDF of link) that contains a section on the wrong way to pick random individuals that is worth the couple of minutes it will take you to read it; particularly if your undergraduate course that talked about collecting field samples is feeling a little dim and hazy.
This resource appear to be gone as at 23rd Feb 2018 😦
[If you are feeling bemused by the differences between non-probabilistic sampling, simple random sampling, stratified random sampling, systematic sampling, and stratified systematic or systematic unaligned sampling, Texas Uni has a page that explains these different Sampling Strategies using an archaeological example. Each short text description is accompanied by a graphic that shows you the sampling strategy in action when you mouse over it. Worth checking out if you are having trouble picturing the differences.]
Remember, GPS’s aren’t just useful for collecting stuff when you’re out there. If you want to talk with one of the Tech Staff about how to pre-load your sampling strategy into a GPS so that you can follow your fieldwork plan more efficiently, come see us in SAL 🙂
(links updated Feb 2018)