## Tuesday, 2 July 2013

### "Dengue" Data: Let's Compare and Find out "What's Wrong"

source: LKY

The number of dengue infections has risen to an alarming number in 2013. NEA has been providing the public with updates, and at the same time sending alerts via the media to caution and educate the public.

The line graphs below is one set of information that it has been updating the public.
Make a 'guess', what's the intent behind communicating this figures to the public?

Examine these two line graphs carefully.
While they "attempt"the report similar information, there's something not quite right in the way data is presented in one of the graphs.
Can you tell "What's Wrong" with which graph?

Source of Data: http://www.x-dengue.com/Home/Summary (correct as on 5 June 2013)

1. The intent of commmunicating these figures to the public is to give them a wake up call so that they will realise that the dengue situation is getting very bad , the cases are much higher than last year thus if the public does not play a part individually to stop the breeding of mosquitos , the number of cases will just continue to rise and pose a great health threat.

The average (22 week and 52 week) of both years are both different , but i think thats the only mistake and it can be forgiven as 2013 is only half way through while on the other hand 2012 is over already and they are able to take a full 52 week reading.

1. The two graphs should be made/put side by side so a person can see from one glance the difference in the number of dengue cases and be able to compare both , and realised the gravity of the situation.

2. I agree with your observations that it would certainly be easier to analyse if the graphs are side by side.

2. The first graph is wrong because it does not show the data for all 50 weeks but the second graph shows all the data for all 50 weeks.

1. The first diagram also shows only an average of 22 weeks but the second shows an average of 50 weeks.

3. The intent is to inform the public of the seriousness of the increase in dengue cases in 2013 from 2012. In the first graph the numbers are overlapping making it hard to read.

1. Also the averages for both charts are of 22 weeks and 52 weeks respectively. Making the averages represent different time lengths.

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5. The intent of communicating this figures to the public is to scare the public because the graphs show that the number of dengue cases are increasing and if they don't take precaution, the number odf dengue cases will continue to rise.

The 2 graphs have a different week average so the first graph would have a higher number.

6. If we are supposed to compare the graphs, the average weeks should be the same, either 22 weeks or 50 weeks.

7. The first graph is wrong because while the second graph started from 25 and the gap between each number is 25, the first graph starts at 0 and the difference between each number is 200. So at first glance, it seems as though there is not much difference between the number of dengue cases in Singapore from 2012 to 2013. But that is not true and the first group is a little misleading.

1. The week average is also different because the first takes an average of 22 weeks while the second takes the average of 52 weeks.

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9. The intent behind communicating the figures to the public is to let the public be aware of Singapore's current situation about Dengue, so that the people are able to know and take measures and precautions.
I believe that this method of representing data is not effective as the public might not be able to relate and understand how bad the situation is in order to take necessary actions.

1. The graphs also have a different average, although the reason being that 2013 is not over yet, the average will still be of different time lengths, possibly resulting in an inaccurate set of data.

10. The main purpose of the line graph is to tell the public on the dengue cases that are happening in the year 2012 and 2013. However, the first graph only shows 22 weeks, but the second graph shows 52 weeks. This is unavoidable because 2013 is only halfway completed.

11. For both graphs, the value at the start is not labled although it is clear that the value is 75 at the first dot in the second graph. Also, the graphs are too cluttered to display information clearly.

For the first graph, they added extra weeks into the graph when they are only presenting the data of only 22 weeks. That resulted in a mess in the data shown and might confuse some people.

12. The intent was to warn people that the number of dengue cases was abnormally high and people should take action.
The mistake is the 22 weeks and 52 weeks average, and both should be either 22 weeks or 52 weeks average, but the data given in the first graph is not completed, so it is wrong, but understandable.

13. I think the intent of communicating these figures to the public is to let them know the increasing numbers of dengue infections and trying to ask them to clear stagnant water every few days to prevent the mosquitos from breeding and infecting people.

The graphs have different numbers of cases in the y-axis and the difference is very high so it is not possible to compare it to the previous years to show the difference in dengue infections and the increasing number of dengue infections and may defeat the whole purpose of the 2 graphs.

14. In the first graph, the number of cases marked on the graph are in terms of 200s whereas the markings on the second graph are in terms of 25. By doing so, the graph line will be different as if there is a large increase of dengue cases, the graph line will only increase by a bit. I guess the intent behind drawing the graph this way is so as not to raise too great an alarm in Singaporeans.

15. The intent of the figures is to show the startling increase in dengue outbreaks in 2013 from 2013.
The first diagram is sort of incomplete and the number of cases in the axis is too vague, from a range of 200. But the second graph marks the figures from a range of 25, making the graph a little more accurate and comprehensive.

16. Graph one shows the average number of cases of the 22 week out break while graph two shows the average number of cases of the 52 week out break. There is no way the public could tell that which outbreak is worse.

17. The purpose of showing these figures is to warn the public of the the serious increase of dengue cases. They are to warn the public to take more precautions to avoid further outbreaks of dengue cases. It is also trying to show the increase of dengue cases from the year 2012 to 2013.

The averages between the two figures are incomparable as the timeframes for the two figures are different.

18. 1. The intent behind communicating these figures to the public is so that the public are aware of the current and past dengue situations. They can observe the information and know when to take measures to prevent them from getting dengue.

2. The numbers on the left side of these graphs or the Y-Axis are different, making it impossible to compare the current year to the previous year.

19. The 2013 graph marks out every 200 cases while the 2012 graph marks out every 25 cases.The line graph shows the great increase in the number of cases,this is trying to give the public a sense of urgency to start stopping the breed of mosquitoes.

20. Graph on new dengue cases in 2013 is not efficient in communicating the information as the graph plotted based on dengue cases in 2012. The information on graph for 2013 is very "jumbled" up together, thus making it hard for readers to make out the number of cases that happen each week separately. In my opinion, I think X-Dengue should spread out the information for easier readings. For example, they should forfeit those unused "weeks", and "spread" out the number of cases that happen. Information would be easier to read if so.

21. The intent of communicating these figures is to show the public the massive increase in the number of cases since last year (2012) and till current (July-2013). Only half a year has passed by and yet the number of cases this year is almost twice as much as the cases last year, and the average of the cases in the 2013 is 4 times much more that that in 2012. This is a shout out to the community to alert the people to stop mosquito breeding so that the vulnerable breeding sites is decreased if everyone works together.

From the eyes of the public, normally people do not take not of the labelling of the number of cases at Y axis. They would just take note of the number increase and decrease of the height of the line instead and assume that both the Y axis in the both line graphs would be the same.
This causes the people to assume that the number of cases is not that high.

22. The graphs need to either start from 0 or 25 as it may confuse the public and it is not easy to compare. The number of cases shown at each point of the graph is also very small and hard to read. The numbers are sometimes merged together so someone may not know the actual value of dengue cases.

23. What is the intent behind communicating this figures to the public?
It is to tell the public that the number of dengue mosquitoes are increasing rapidly in 2013. If you compare the 52 week average (for 2012) to the 22 week average (for 2013), the average number of cases a week in 2012 is only around 89, while the average for 2013 is more than 300, almost reaching 400.

"What's Wrong" with which graph?
The 2 graphs have different number of weeks. As the number of cases of dengue might go down in the later part of 2013, the average might go down too.

24. Good observations from all. I see key words like 'alarm', 'confuse', 'raise awareness', 'basis for comparison'.
The graphs are used to communicate information in visual form - keep in mind of the target audience and the intend.

25. The purpose of communicating these figures is to allow the public to be aware of the increasing dengue cases, so that they will take more precaution in the future.

The graphs are separate, causing the public to have difficulty in comparing both.

26. The intent behind communicating this figures to the public is to warn them that there are many people being infected by Dengue so they would be extra cautious in the future.

The difference between the figures on the Y axis of the 2013 line graph is much greater than those on the Y axis of the 2012 line graph. Thus, the reader cannot tell the difference in the number of dengue cases in 2013 and 2012 at one glance.