3.1 Data visualisation
The EHINZ team currently uses several data visualisation tools, which include:
In general, tables, graphs, and maps should be able to stand alone. This means that the table/graph/map and its key components (ie, titles, headings, axes labels, legends, and footnotes) should contain all the key information needed.
Tables are useful when readers need precise values, or when we want to show different types of information. Tables are generally not the best way of showing patterns or trends over time – a graph may be better for this.
Graphs are helpful in ‘telling a story’, highlighting trends over time, and making comparisons. A well-presented graph should make the key information ‘hit you in the face’ – you should be able to grasp the key message of the graph within a split second of looking at it.
Consider using a graph when you want to illustrate:
Types of graphs
- to compare different values (eg, age-standardised results)
- to emphasise individual values
- when the variable on the horizontal axis is categorical
Horizontal bar charts
- when there are too many bars to fit comfortably from left to right
- when the labels for the bars are very long
- to show the trend of the values
- to show the shape of change from one value to the next
Note: Use continuous or interval variables on the x-axis, like time (eg, year or month) and age (eg, age in years or months, age in equal sized groups), never discrete values (eg, region).
- to show a series of graphs or maps, arranged in a grid – for comparison
Note: All the graphs need to have the same scale for x and y axis.
Stacked bar chart
- to show proportions of a whole
- useful when the focus is to compare the totals as well as provide additional information about the composition of each bar
- present ‘parts of a whole’ type data in a bar chart first.
- comparisons between the different categories can be difficult in a stacked bar chart. Add data labels to help the reader interpret the size of the categories.
Maps are useful when showing spatial patterns in data that might not be obvious in tables or graphs. They allow readers to look up data in specific locations and enable comparison of data across geographical regions.
Consider using a map when you want to:
- show the location and spatial distribution of data
- compare different areas and show clear spatial patterns
- the EHINZ team has developed its own map template.
- by default, quintiles are to be used for classification. However, some data needs to
be normalised. For example, counts of livestock per TA are replaced by density
(number of livestock per km2) to be comparable between areas of different size.
- zero or null values are to be appropriately labelled in order to avoid confusion
between data that is not available, suppressed or an actual zero value.
For more information on selecting and designing tables and graphs, have a look at these resources:
3.2 Writing guide
The Communication Standards for the Ministry of Health is a core reference document for the EHINZ team. It is the basis for our style of communication, certain grammatical preferences, and referencing style.
APPENDIX 3 is a copy of the Ministry of Health Communication Standards.
3.2.1 Font styles
We use Arial font for all documents and presentations, except factsheets. The font for factsheets, EHINZ and Healthspace websites is Source Sans Pro.
3.2.2 Plain English
The EHINZ team adhere to Plain English principles. Therefore, irrespective of the method of dissemination, authors need to:
- identify their intended audience
- keep words simple
- keep sentences and paragraphs short and focussed
- put the most crucial information at the beginning
- have clear and succinct rationale
- proofread their work.
Some helpful resources to help you understand and apply plain English principles are:
- How to tell a story using statistics(Statistics New Zealand)
- Your guide to our Plain English Standard(Statistics New Zealand).
APPENDIX 4A is a copy of How to tell a story using statistics.
APPENDIX 4B is a copy of Your guide to our Plain English Standard.
All EHINZ publications, including the EHINZ and Healthspace websites, contain the following disclaimer:
Environmental Health Intelligence NZ – Rapu Mātauranga Hauora mo te Taiao - Aotearoa, makes no warranty, express or implied, nor assumes any legal liability or responsibility for the accuracy, correctness, completeness or use of any information that is available on or through this [website]/ [report]/ [factsheet].