1. Counting Big Populations: How do scientists estimate the size of a large population?
Scientists take a random sample from a population to estimate its size.
2. Sampling on a grid: To count the dandelions, we'll first create a grid, then use the computer's random number generator to tell us which grid squares to count. We'll do this 10 times, because, as you'll see, the counts in the different grid squares will vary a lot. After you count 10 squares, you'll use the average number per square to estimate the population of the entire lawn.
How many dandelions are there on the grid? 93
3. Scaling it Up: What does it mean that we scaled it up?
Using a small area of the entire portion to estimate the rest of the population.
4. Keeping it Random: Why is it important to randomly select segments to count?
In order to prevent experiment bias, where the experiment has the tendency to choose.
5. When Size Matters: What is the simplest way to determine the appropriate sample size?
The simplest way to determine appropriate sample size is to graph a running average.
6. Bare Bones Sampling: What is the difference between measuring abundance versus Presence/absence?
Abundance: The number of individuals found in a given area
Presence/Absence: Determining small areas or points and seeing if an organism was observed or not
7. Collecting P/A Data: Counting Moss.. How do we estimate sample size?
You pick points that can be used randomly used to sample.
8. Impervious Surface: How do we estimate impervious surface? Explain.
We estimate impervious surface by using the presence/absence method by picking points on the map and looking for the ones that's surface is impervious.
9. Getting Fancy: What are the steps for conducting a simple transect?
1. Randomly select a point
2. Randomly choose a direction
3. Lay out a transect
4. Determine where along the transect you will collect sample data
5. Layout a sampling frame
10. Try a Transect:
Summary: Explain what you learned from doing this activity
In this activity, I was able to learn different methods in order to estimate the population of an area based on its features. Some ways to estimate the population were including: Abundant measuring which is just counting the number of organisms in one area and Presence/absence which is when you pick a small point on the area and conclude if the organism was observed or not. Another way to estimate a population is using a transect. This method helps you find along what area you will collect data and then you place your frames for measuring the overall population.
Scientists take a random sample from a population to estimate its size.
2. Sampling on a grid: To count the dandelions, we'll first create a grid, then use the computer's random number generator to tell us which grid squares to count. We'll do this 10 times, because, as you'll see, the counts in the different grid squares will vary a lot. After you count 10 squares, you'll use the average number per square to estimate the population of the entire lawn.
How many dandelions are there on the grid? 93
3. Scaling it Up: What does it mean that we scaled it up?
Using a small area of the entire portion to estimate the rest of the population.
4. Keeping it Random: Why is it important to randomly select segments to count?
In order to prevent experiment bias, where the experiment has the tendency to choose.
5. When Size Matters: What is the simplest way to determine the appropriate sample size?
The simplest way to determine appropriate sample size is to graph a running average.
6. Bare Bones Sampling: What is the difference between measuring abundance versus Presence/absence?
Abundance: The number of individuals found in a given area
Presence/Absence: Determining small areas or points and seeing if an organism was observed or not
7. Collecting P/A Data: Counting Moss.. How do we estimate sample size?
You pick points that can be used randomly used to sample.
8. Impervious Surface: How do we estimate impervious surface? Explain.
We estimate impervious surface by using the presence/absence method by picking points on the map and looking for the ones that's surface is impervious.
9. Getting Fancy: What are the steps for conducting a simple transect?
1. Randomly select a point
2. Randomly choose a direction
3. Lay out a transect
4. Determine where along the transect you will collect sample data
5. Layout a sampling frame
10. Try a Transect:
Summary: Explain what you learned from doing this activity
In this activity, I was able to learn different methods in order to estimate the population of an area based on its features. Some ways to estimate the population were including: Abundant measuring which is just counting the number of organisms in one area and Presence/absence which is when you pick a small point on the area and conclude if the organism was observed or not. Another way to estimate a population is using a transect. This method helps you find along what area you will collect data and then you place your frames for measuring the overall population.