What makes a good viz?

What makes a good viz? - Part 2

25th August 2017 | Chris O'Mahony

Size and colour used to represent the same measure

Question complexity

Every addition in complexity to a visualisation should add value. For every extra dimension or measure that is added to a visualisation, the user will require more time and thought to process the information that is being presented to them. If that added complexity does not add value to the message of the visualisation or dashboard, this is essentially wasted time. As a general rule of thumb, do not do one thing in two different ways on the same single visualisation. For example, a bar chart showing Students by academic achievement, does not need the bars coloured by academic achievement as this doesn’t add any additional value.

These two users will probably want to see different levels of detail.

Consider your user

Consumers for published dashboards and reports can vary dramatically. Some users will be happy to delve into the details of issues and have the time and inclination to do so, whereas others will just require figures represented at a high level and immediately digestible.

Use sequential colours rather than a random colour palette.

Consistency

When creating a dashboard, ensure that consistency is applied, particular in relation to colours. If a colour palette is used somewhere within your dashboards to represent something, it should be used elsewhere to represent same element. If this cannot be followed, ensure that legends are placed in appropriate positions, so that the colour identification is clear.

Colour Sequencing

If using colours across a sequence, such as a number of years, use sequential colours rather than a random colour palette. This should make it easier for the user to intuitively interpret the data and the dimensions it describes.

Gutenberg diagram, an age-old concept developed by Edmund C. Arnold.

Signpost functionality

It is very easy when you are creating a dashboard to know how everything interacts and what behaviour is to be expected. However, for a new user approaching a dashboard cold, this can often be a tricky process. It is best to offer some kind of guidance on the dashboard to functionality or features that they may not be expecting.

Read top-left to bottom-right

Conventionally, our culture automatically reads from the top-left to bottom-right. We can take advantage of this trait in dashboard design by putting the key, high level information at the top-left of the dashboard (for example KPI boxes). As the eye travels to the bottom-right, it is a natural place to put the visualisations that are at the lowest level of granularity (such as a scatter plot).

Thanks for reading! Any questions, please get in touch at vizi.education.

The ECT guide to report writing

How do you get started on writing school reports?

3rd December 2019 10 mins
Blog post

Peer to peer grading

23rd October 2019 10 mins
How to

Track SEN cohorts

Track by SEN/Demographics in Vizi

7th August 2019 5 mins
How to

Setting targets and metrics

Track progress against targets with Vizi metrics.

7th June 2019 10 mins
Blog post

Encouraging marking standardisation

1st February 2019 10 mins
Blog post

Managing student wellbeing with data

How can data help with student wellbeing?

4th December 2018 10 mins
How to

Creating a seating plan

Make beautiful seating plans in seconds

30th June 2018 5 mins
How to

Creating an assessment

Learn how to create assessments easily in the Vizi markbook

12th April 2018 10 mins
Blog post

How can data-viz help improve student outcomes?

3rd February 2018 5 mins
Blog post

The blog