Data Processing Flashcards
What is a dot distribution map?
Maps in which each dot represents a unit of the variable, specified in the key. Patterns show distribution (clustered, random, regular…)
Advantages of a dot distribution map:
+ raw data is retained
+ spatial distribution is obvious
+ quick to draw
+ highly versatile
Disadvantages of a dot distribution map:
+ requires explanation of location
+ time consuming to count dots
+ larger regions appear to have higher frequency
+ dots can merge
What is a proportional circles map?
A map in which the value of a variable is represented by the size of its circle on a map.
Advantages of a proportional circles map:
+ spatial patterns are obvious
+ relative key allows comparison
+ highest abs lowest values can be identified
+ effective when using a small number of sites
Disadvantages of a proportional circles map:
+ symbols overlap
+ map becomes clustered, patterns not obvious
+ underlying features are obscured
+ precision of location reduced by symbol
What is an isopleth map?
A map I that features colour coded lines of value. The lines are accompanied by a key.
Advantages of an isopleth map:
+ quick to complete
+ fixed intervals means changes are obvious
+ spatial patterns can be identified
+ raw data is retained
Disadvantages of an isopleth map:
+ subjective - people choose different line values
+ complex patterns may be hidden
+ intermediate values are lost
+ small lines are hard to interpret
What is a scatter graph?
A graph that features a line of best fit, and a surrounding pattern of dot values
Advantages of scatter graphs:
+ large amounts of data plotted in a small space
+ anomalies can be seen
+ patterns are obvious
Disadvantages of scatter graphs:
+ only two variables can be displayed
+ easy to make mistakes when creating
+ best fit line may show misleading relationship
What are the two main types of scatter graph correlation?
Positive and negative
What are the three subcategories of positive or negative correlations?
Strong, moderate and weak
What is a bipolar analysis graph?
A horizontal axis graph that features a negative and a positive axis.
Generic advantages:
\+ easy to complete \+ raw data is retained \+ distribution/patterns are evident \+ allows easy comparison \+ large amounts of data can be plotted
Generic disadvantages:
\+ difficult to interpret \+ symbols merge \+ raw data is lost \+ precise values are lost \+ easy to make mistakes when completing
What processing method is used with the nearest neighbour index?
A dot distribution map
What processing method is used with standard deviation?
Scatter graph
What processing method is used with chi squared, spearman’s rank and Pearson’s coefficient?
Hypothesis testing
What processing method is used with an environmental quality survey?
Bipolar analysis
