WEEK 2 Flashcards
Post week learning reflection
What is probability?
Probability is the likelihood of getting a certain result by chance.
Has a role in predicting ecological outcomes.
Probability quantifies uncertainty and aids in the estimation of species abundance within an ecosystem.
What is a random variable? Give an example
Random variable is a parameter of interest within a study. It is a tool to measure ecological phenomena, where the outcome is uncertain.
Example: the number of a particular species in a given area
What is a sample space? Give an example
Comprehensive list of all possible outcomes. In ecology, it could include all species within a community.
For example, if a dice has 6 sides and you throw 2 die, the sampling space is 12.
What is unbiased sampling and why is it important?
Unbiased sampling means that every individual or item in a population has an equal chance of being selected for the sample.
Critical to avoid misrepresentation of population sizes and dynamics.
What is the mean and what information does it give us?
The mean is the sum of all observed values divided by the number of observations.
It provides a measure of central tendency, indicating the average number of observations of the variable of interest.
How do you calculate the mean?
mean = sum(observations)
/number_of_observations
What is variance and what does it tell us about our data?
Variance quantifies the degree to which each variable count differs from the mean, indicating the spread of the data. It reflects the variability in the sampled population.
How do you calculate the variance?
var = sum(observations - mean)^2)
/(number_of_observations - 1)
What is the standard deviation? What does it measure and what does it tell us about our data?
Standard deviation is the square root of the variance.
It measures the dispersion of the variable counts relative to the mean, indicating how much the counts vary from the average number observed. In other words, it reflects the typical distance an observation is from the mean, which in this context helps understand population stability
How do you calculate the standard deviation?
SD = srt(sum(observations - mean)^2)
/ (number_of_observations - 1)
Or
St dev = squareRoot(variance)
What happens when the sample size increases?
As the sample size increases, the sample mean gets closer to the population mean.
The average number of the observed values becomes more accurate as the number of observations increases.
Summary of key points for week 2
Probability and Statistics:
These aren’t just numbers and equations; they are your compass in the complex world of ecology.
They empower you to measure uncertainty and make predictions that inform how we understand and manage ecosystems.
Summary of key points for week 2
Species Abundance Factors:
Remember, the lives of species are shaped by their environment—where they live, what they eat, and who shares (or threatens) their space.
Our simulations are a window into these intricate dynamics, offering a glimpse into possible futures for these species.
Summary of key points for week 2
Analytical Tools:
The mean, variance, and standard deviation are more than statistical terms; they are lenses through which you can observe patterns and perturbations in nature.
They allow you to quantify what you observe and uncover the stories behind the data.
Summary of key points for week 2
Statistical Theorems:
The Law of Large Numbers and the Central Limit Theorem are your assurance that the patterns you see in ecological data are not fleeting mirages but reflections of deeper truths.
These theorems ensure that the insights you gain from long-term studies stand on solid ground and that your conclusions will hold water when scrutinized.
