Data Handling Flashcards
What are the advantages and disadvantages of graphical techniques?
Advantages:
- Shows data visually to help understanding
- Helps non-specialists and non-geographers to understand more complex data
- Quickly summarises data
- Compare data sets
- Understand/compare patterns in data
- Assess data over time
- Aid further statistical testing
Disadvantages:
- Time consuming and/or difficult to create
What are the advantages of dot maps?
Advantages:
- Effective in showing the spatial density.
- Shows variation and pattern.
- Easy to interpret.
- Purpose is easily understood.
- Easy to generate on a computer.
What are the disadvantages of dot maps?
Disadvantages:
- Actual values can’t be seen.
- Dots crowded/can lead to clustering – not very accurate.
- Time consuming if done by hand.
- Small countries aren’t represented accurately.
- Easy to make a mistake/be subjective.
What are the advantages of isoline maps?
Advantages:
- Drawn easily on computers.
- Can see areas of equal value.
- Can see gradual changes.
- Avoids the problem of
boundary lines.
What are the disadvantages of isoline maps?
Disadvantages:
- Do not show discontinuous
distributions. - Only work where there is
plenty of data spread over the
study area and the changes
are gradual. - Small lines and numbers on
graphs can be difficult to
read.
What are the advantages of choropleth maps?
Advantages:
- Visual impression of change over a
space- gives general impression. - General anomalies can be
identified. - Easily done by hand or on the
computer. - Doesn’t breach data protection.
- Good for data which involves
density reading. - Easy to interpret via a key.
What are the disadvantages of choropleth maps?
Disadvantages:
- Gives false impression of abrupt
change at the boundaries. - Variations within each area are
hidden. - Reading exact figures is impossible.
- Assumption of uniform conditions throughout an area.
What are the advantages of proportional symbol maps?
Advantages:
- Very visual
- Can represent a large range
of data. - Not dependent on size of
the area.
What are the disadvantages of proportional symbol maps?
Disadvantages:
- Difficult to produce.
- Impossible to extract exact data
- Overlap can occur making it
confusing and difficult to
read/interpret.
What are the advantages of flow maps?
Advantages:
- Very visual impression
- Can show movements easily such as
traffic/migration etc. - Desire lines show trends in migration
of population. - Gives clear sense of direction.
- Clear location component.
What are the disadvantages of flow maps?
Disadvantages:
- Hard to draw.
- Flows can be in the same
direction/overlap. - May be difficult to show meeting
point of the wide bands without
overwhelming the map.
What are the advantages of sphere of influence maps?
Advantages:
- Visual representation of trends.
- Can be used at different scales.
- Can be used for a variety of services.
What are the disadvantages of sphere of influence maps?
Disadvantages:
- Time consuming and complex to construct.
- Does not explain the reasons behind the trends.
What are the advantages of cross sections?
Advantages:
- Easy to overlay annotations.
- Easy to ascertain trends, patterns and relationships.
- Versatile in use - different scales/areas.
What are the disadvantages of cross sections?
Disadvantages:
- Subject to human error.
- Steep slopes are more problematic to mark the contours on.
- Difficult to read with many annotations.
What are the advantages of annotated overlays?
Advantages:
- Brings out key features/points showing you understand the context.
- Can be linked for context to the written paragraph-supporting the point.
- Highlight aspects linked to your chosen context.
What are the disadvantages of annotated overlays?
Disadvantages:
- Hard to find enough to annotate.
- Requires more space.
- Hard to balance between labelling and explaining in detail.
- Too much detail can detract attention from the map.
What are the advantages of transects?
Advantages:
- Provide a visual overview of the area.
- Can show a section of a river/valley or part of a rural/urban landscape.
- Several transects from a central point can be compared.
What are the disadvantages of transects?
Disadvantages:
- A single one has limited value.
- Incorrect or exaggerated scales can be misleading.
- Only takes a single point in time.
- Time consuming and difficult to represent reality accurately.
What are the types of data?
Nominal Data - named data which cannot be placed in order.
Ordinal Data - named data which can be placed in order.
Ratio Data - real numbers with a true zero.
Interval Data - real numbers with no true zero e.g. temperature (there is always a temperature).
What are the types of sampling?
Random - sampling without bias.
Systematic (Regular) - sampling at regular intervals.
Stratified - random selection from sets of organised groups.
What are the advantages and disadvantages of calculating the mean?
Advantages:
- Basic calculation is easily understood.
- All data values are used in calculation.
- Used in many statistical procedures.
Disadvantages:
- May not be a meaningful value e.g. 2.4 children per family.
- Affected strongly by extremities in data.
What are the advantages and disadvantages of calculating the median?
Advantages:
- Concept is easy to understand.
- Can be determined for all but nominal data.
- Not influenced by extremities.
Disadvantages:
- Data must be arranged in rank order.
- Cannot combine medians in statistical calculations.
What are the advantages and disadvantages of calculating the mode?
Advantages:
- Easy to understand.
- Not affected by extremities.
- Can be obtained for qualitative data.
Disadvantages:
- Not all data sets have a modal value.
- Some data sets have multiple modal values.
- Multiple modal values are often more difficult to interpret.
What is a null hypothesis?
A statement expressing no relationship between factors.
What is an alternative hypothesis?
A statement expressing a relationship between factors.
What are the advantages of Spearman’s rank?
Advantages:
- Relatively quick and easy calculation if data set isn’t too big.
- Uses data that can be ranked easily.
- Doesn’t assume normal distribution.
- Spearman correlation can be used when the assumptions of the Pearson correlation are markedly violated.
What are the disadvantages of Spearman’s Rank?
Disadvantages:
- It requires a sample of at least 7 - less than 7 observations can make meaningless
correlations. - Only tests linear relationships and two sets of variable data.
- Can be difficult to work out for large data sets.
- Doesn’t use the actual values.
- Correlation does not imply causality.
What are the advantages of Pearson’s Correlation Coefficient?
Advantages:
- Uses actual values of data.
- It not only indicates whether there is a correlation between any two variables, but also determines the exact extent, or degree, to which they are correlated.
What are the disadvantages of Pearson’s Correlation Coefficient?
Disadvantages:
- More complex and time-consuming calculation than Spearman’s, so more likely to make an error.
- Assumes values are normally distributed.
- Affected strongly by extremities.
- Only tests linear relationships and two sets of variable data.
- It is based on a large number of assumptions.
What are the advantages of Linear Regression?
Advantages:
- Better than using your own judgement.
What are the disadvantages of Linear Regression?
Disadvantages:
- Cannot be used for non-linear relationships.
- Does not explain the correlation.
- Sensitive to extremities in data.
What are the advantages of the Chi Square Test?
Advantages:
- Tests the relationship between variables.
- Easy to compute and interpret.
- Not affected by distribution (less work for students to do).
- Can be used for nominal and interval data.
What are the disadvantages of the Chi Square Test?
Disadvantages:
- Cannot compare more than two categories.
- Greater than 20 observations required.
- Invalidated if expected values are less than 5 (lost time since this is only noticed during calculation)
- Does not determine strength of the relationship.
What are the advantages of Nearest Neighbour Analysis?
Advantages:
- Very flexible - any data type can be used as long as its locational.
- Doesn’t need normal distribution (less work for investigators).
- Simple calculation with few steps.
- With a large sample size it is very reliable.
- The index can be compared between areas of similar size.
What are the disadvantages of Nearest Neighbour Analysis?
Disadvantages:
- Can be time consuming with a large data size.
- Size of area can alter data if too large.
- Only useful to understand distribution.
- Doesn’t show relationship between factors or give reasons.
