Data journalist Chris McDowall discovers an unreliable illustration supplied by the Ministry of Health to show vaccine rollout was created by a graphic designer, not a statistician.
On March 17, the Ministry of Health published a chart showing projected timings for New Zealand's vaccination programme. The graph was titled "Covid-19 vaccine: Illustration of volumes and timing of vaccination rollout".
Minister Chris Hipkins made several references to the graphic during that afternoon's media update.
Irregularities in the chart's design raised eyebrows among data specialists. These irregularities included a note that the graph showed "Cumulative doses administered" when it appeared to show rolling snapshots.
The Herald wrote to the Ministry of Health requesting a copy of the data used to create the rollout graph. Seven minutes later a representative from the ministry's media team replied that they could not supply and the Herald would need to request the data under the Official Information Act.
Last night the Herald received the results of that request. Here are the most important lines from their response.
"The 'Covid-19: Illustration of volumes and timing of vaccination rollout' chart was intended to be an illustration and approximate. It was generated as a graphic design rather than a statistical product."
The response continues that, given the chart was produced as a "graphic design", the ministry is "unable to provide specific data that reflects the graph".
In short, the rollout chart does not show actual forecasts. It shows lines drawn by a graphic designer dressed up as actual data. Although the chart has the word "Illustrative" in the title, there is no indication the chart is effectively a sketch.
Such a cavalier attitude towards information graphics is concerning.
When the Government shares public health information in the form of a graph, it implies a certain level of rigour and accuracy. In this case, the implication was the vaccination rollout plan projections were mature enough that the data could be graphed and shared. This does not appear to have been the case.
Sometime this week, the Ministry of Health removed the graph from its website, although it remains available through the Internet Archive.
While the Ministry of Health has been under considerable pressure to share timings on its vaccine rollout, it is unfortunate it published this information in the form of an unreliable illustration created by a designer rather than a statistician.