Random Sampling Challenges and Examples

06/07/24 • 21 min

Delving into the significance of random sampling, hosts Matt, Grant, and Randy, use real-world examples to illustrate challenges associated with sampling, stressing the importance of random sampling for accurate representations of wildlife populations.

Episode quotes

"...my question for the group is, do you think, they can actually achieve their objectives with a sample size of one, with one transect inside a particular city. Do you think they can achieve that at the city scale?"

" Inside that rectangle, they're placing, camera traps to monitor species richness across that gradient of habitat from the lowlands to the uplands."

"...so to bring this home from where we began (referring back to episode 1), we had a garden with tomatoes in it, and now we have a city with wildlife in it. And so the garden area is is akin to our city area, and our the number of tomatoes in the garden that we wanna know the number of is is a parallel to the wildlife we want to sample in that city."

Episode music: Shapeshifter by Mr Smith is licensed under a Attribution 4.0 International License. https://creativecommons.org/licenses/by/4.0/

https://freemusicarchive.org/music/mr-smith/studio-city/shapeshifter/

Cite this episode: https://doi.org/10.7944/usfws.wbtn.s01ep02

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Episode quotes

" Inside that rectangle, they're placing, camera traps to monitor species richness across that gradient of habitat from the lowlands to the uplands."

Episode music: Shapeshifter by Mr Smith is licensed under a Attribution 4.0 International License. https://creativecommons.org/licenses/by/4.0/

https://freemusicarchive.org/music/mr-smith/studio-city/shapeshifter/

Cite this episode: https://doi.org/10.7944/usfws.wbtn.s01ep02

Citation formatter: https://citation.doi.org/

Previous Episode

Random Sampling

Hosts Matthew Butler, Grant Harris, and Randy Stewart set the stage for Wildlife by the Numbers emphasizing the importance of proper scientific approaches in wildlife ecology and sharing anecdotes to create awareness about the challenges and rewards of ecological research.

Episode quotes:

"Today, we're gonna talk about an issue that we often confront with biologists, particularly young biologists that are just getting into wildlife work and understanding statistics and science well, conservation science design of of studies, and that is random sampling and the importance of random sampling and why it matters. To help introduce this topic, we'll start with, a simple example, and then we'll get into more wildlife oriented issues. So for the simple example, I have a big garden, and it's large. It's it's an acre in size."

"Okay. So now that we know we need to to sample, so to not count everything but parts of it, and we want those parts to be representative, how do we then get that representative sample? What do what procedure do we have to use to make sure that sample represents the population at large?"

"And so that's why we were talking about we wanna make sure that when we sample, we are doing it in a random way to account for the differences in number of tomatoes on each plant to make sure we have an accurate representation of the true count in that garden."

Episode music: Shapeshifter by Mr Smith is licensed under a Attribution 4.0 International License. https://creativecommons.org/licenses/by/4.0/

https://freemusicarchive.org/music/mr-smith/studio-city/shapeshifter/

Cite this episode: https://doi.org/10.7944/usfws.wbtn.s01ep01

Citation formatter: https://citation.doi.org/

Next Episode

Sample Size Needs

Shifting focus to sample size determination, Matt, Grant, and Randy explore the challenges and considerations in choosing appropriate sample sizes for reliable ecological research. They discuss trade-offs, budget constraints, and introduce the concept of power analysis for enhancing the reliability of ecological studies.

Quotes from this episode:

"In this podcast, we're going to talk about sample size needs. How many samples does a person need to collect to get a representative sample of the population? So it leads us back to this whole representativeness idea. If a person samples too few, then there's a very good chance that person is going to include a disproportionate number of outliers, oddballs or anomalies in the sample."

"...in the earlier episode we said, if all the plants have the same number of tomatoes we would just have to sample one of them. That was an invariant population. But we also spoke to that some plants had 100 tomatoes and some had none. And so we have extreme variability."

"... (the amount) of uncertainty you're willing to deal with, and how much imprecision you're willing to deal with really drives your sample

size needs....You've got to take both of those things into consideration. How variable is my population and then how certain do I want to be? How much error am I willing to accept in my final estimate?"

Episode music: Shapeshifter by Mr Smith is licensed under a Attribution 4.0 International License. https://creativecommons.org/licenses/by/4.0/

https://freemusicarchive.org/music/mr-smith/studio-city/shapeshifter/

Cite this episode: https://doi.org/10.7944/usfws.wbtn.s01ep03

Citation formatter: https://citation.doi.org/