# Geography Fieldwork

GCSE

# Graphs

## 1. Graphs

### Data

**Quantitative data** records quantities (e.g. numbers, sizes, frequencies).

**Qualitative data** records subjective qualities (e.g. opinions and attitudes).

**Discrete data** can only take certain values (e.g. whole numbers)

**Continuous data** can take any value (e.g. length, width, time)

### Justifying your choice of data presentation

Your findings can be presented with a range of graphical and mapping techniques. Each form of data presentation needs to be justified. Here is an example.

Fieldwork technique |
Systematic sampling along a transect from the PLVI to the edge of the CBD. An environmental quality score was calculated at every 30 metres. |

Data presentation |
Line graph with distance from PLVI on x-axis and environmental quality score on y-axis. Points were joined up |

Bad justification |
The line graph shows how environmental quality changes as distance increases from the PLVI. |

Good justification |
A line graph is appropriate because both distance from the PLVI and environmental quality core are numerical. The points were joined up because distance is continuous data. |

### Bar charts

Bar charts are use to show the numbers of things (or *frequency*) in several *categories*

- Plot the categories on the x-axis
- Leave gaps between the bars as data are not continuous (called
*discrete data*)

### Divided bar charts

Divided bar charts are used to show the frequency in several categories, like ordinary bar charts. It is a type of compound bar chart. But unlike ordinary bar charts, each category is subdivided.

- Plot the categories on the x-axis
- Leave gaps between the bars as data are
*discrete data* - Use colours or shading to show the subdivided categories, and include a key

### Percentage bar charts

Percentage bar charts are use to show the percentage of each subdivision in several *categories. *It is a type of compound bar chart.

- Plot the categories on the x-axis
- Leave gaps between the bars as data are
*discrete data* - Use colours or shading to show the subdivided categories, and include a key
- Each bar should be the same height (i.e. 100%)

### Histograms

Histograms are used to show the numbers of things (or *frequency*) along a continuous scale

- Plot the sliding scale on the x-axis
- Do not leave gaps between the bars as data are
*continuous data*

### Pie charts

A pie chart is a circle divided into sectors. Each sector represents a percentage.

- Sectors can be shaded or coloured, and need labels or a key
- Multiple pie charts can be used where the size of each circle shows
*ratio*.

### Line graphs

- Both axes are numerical.
- If time is one of the variables, always plot it on the x-axis.
- Only join up the points if the data are continuous.

### Scatter graphs

- This needs one independent variable (on x-axis) and one dependent variable (on y-axis).
- Both axes must show continuous data.
- Do not join up each point, but use a line of best fit instead.