Revision Flashcards
What is the Chi-Squared Analysis used for?
Used by comparing observed data we would expect to obtain with the data we might expect
What is standard deviation used for?
Used to describe the spread of data around a central value
What is Spearman’s Rank Correlation Coefficient used for?
Used to describe the strength and direction of a relationship between 2 variables
What is Pearson’s Product Moment Correlation used for?
Used to measure the strength of a linear relationship between 2 variables
What is Linear Regression Analysis used for?
Used to determine the linear relationship between one dependent variable and one independent variable
What is Nearest Neighbour Analysis used for?
Used to measure the distributions according to whether they’re clustered, random or regular
What are the advantages/disadvantages of Chi-Squared Analysis?
- Useful in measuring differences between observed and expected
- Useful when data can be grouped into classes
- Cannot use percentages
- Difficult formula
- Data must be in the form of frequencies
What are the advantages/disadvantages of standard deviation?
- Shows how much data is clustered around a mean value
- Gives a more accurate idea of how data is distributed
- Can be hard to calculate
- It doesn’t give you the full range of data
What are the advantages/disadvantages of Spearman’s Rank Correlation Coefficient?
- Shows the significance of the data
- Doesn’t assume normal distribution
- Can be hard to calculate/difficult formula
- Needs 2 sets of variable data to be performed
What are the advantages/disadvantages of Pearson’s Product Moment Correlation Coefficient?
- Can be hard to calculate
- Assumes a linear relationship between variables even if this does not exist
- Indicates the presence/absence of a correlation between 2 variables
- Compared to other methods it is time consuming to get results
What are the advantages/disadvantages of Linear Regression Analysis?
- Simple to implement
- Easy to interpret output coefficients
- Less complex compared to other algorithms
- Linear relationship between variables is assumed which isn’t always the case
What are the advantages/disadvantages of Nearest Neighbour Analysis?
- No account is taken of the influence of the physical landscape on the location of features which can distort results
- Analysis is not precise when there is more than one cluster
What are the advantages of kite diagrams?
- They clearly show the amount and distribution of a plant species
- It’s easy to make comparisons along the line of transect between different plant species
What are the disadvantages of kite diagrams?
- They can be time consuming to draw
- There is a lot of information to display therefore coming up with a suitable scale can be tricky
What are the advantages of polar graphs?
- Can be used to show the magnitude as well as direction
- They allow comparisons to be made
What are disadvantages of polar graphs?
- They are time consuming to draw compared to other methods of displaying data
- The scale must relate to the radius of the circle
What are the advantages of triangular graphs?
- They are efficient as they display a lot of information and can be drawn on one page
- They can be used to show data that’s been divided into 3 parts
- Once plotted, value groupings are easily identified
What are the disadvantages of triangular graphs?
- They can be time consuming and confusing to draw
- The data must be in percentage form
What are the advantages of dispersion graphs?
- They are an easy way to compare two sets of data
- They allow you to determine the median and the upper and lower quartiles
- They show the range of data
What are the disadvantages of dispersion graphs?
- The scale must be chosen carefully in order to be effective
- Clustering can make the graph hard to read
What are the advantages of bipolar analysis?
- They are an effective technique for comparing 2 or 3 sets of data
- Easy to make a visual comparison by looking at the lines
What are the disadvantages of bipolar analysis?
- Can be hard to read if the comparison is between 2 sets of similar data as lines may overlap
- An appropriate scale must be chosen carefully
What are the advantages of logarithmic graphs?
- They can be used to show data with a large range of values
- They let us plot a straight line instead of a curve
- They allow us to compare data that couldn’t normally be compared on the same diagram
What are the disadvantages of logarithmic graphs?
- Scale must be considered carefully when comparing data
- Graph can become clustered where symbols overlap
- Must be drawn on logarithmic graph paper
