There are some charts that look so stunning and yet confusing. You cant make up your mind whether it tells a compelling story or it is just plain wrong.
Today, let me present you one such chart. I call this Pie of a Pie of a Pie chart (source: thiswoo, thanks to Nassar, our forum member for mentioning this)
Pie of pie of pie – What is good about it?
The idea of this chart is quite noble. Show how the water in this world is distributed. Obviously, with such large numbers, making one chart would be difficult. So make 3. The initial pie of salt vs. fresh water, which explodes to show the distribution of fresh water which explodes to show the spread of other water sources.
The chart narrates the story of how little water is available for consumption and where it is one simple picture.
And the pie leaking in to another pie metaphor works really well in this case.
What is not good about it?
To begin with, the 3D pies are very deceptive. It is not clear how much % of water is fresh water (other than the fact that it is very little). Also, compared to a 2d pie, the fresh water slice in 3d pie looks bigger (due to its orientation and 3d effects).
Then, no matter how good the colors are, the 2nd and 3rd pies are confusing. The colors imply that the blue slice (fresh water) corresponds to just ice caps and glaciers.
Since all 3 pies are of similar sizes, we immediately think that we have enough water. Only on closer inspection it becomes obvious that the size of lower pies has no relation to actual water amount (only angles convey the information).
Finally, I think this chart is bad because it takes excessively large amount of time to make in almost any software. That said, it is a good exercise to come up with this tinkering with various drawing shapes etc.
Aren’t there any alternatives?
The easiest and clear (and obviously not so exciting as pie of pie of pie chart) alternative is to just show the numbers like this:
Note: This table too is misleading as row heights wrongly indicate that we have more fresh water than salt water etc.
The next option is to use a variation of bar of bars, some thing like this:
One more option I can think of is a tree map. For hierarchical data like this Treemaps are also a very good option. That said, since the largest value is 390,000 times the smallest value, any treemap will be very large to show the smallest value clearly.
Do you like Pie of Pie of Pie chart?
What do you think? Do you love this or would you prefer some other chart to visualize this data? Share your opinion using comments.
Previously on Pie Charts
Pie charts are one of the most (mis)used charts in business world these days. That is why we talk about them from time to time. See these articles to learn more:
- An example where pie charts work well
- Alternatives to Pie charts
- Group smaller slices in pie charts to improve readability
- Do not make pie charts like these
PS: If you want to know to create this pie of pie of pie chart in excel, see here.
12 Responses to “29 Excel Formula Tips for all Occasions [and proof that PHD readers truly rock]”
Some great contributions here.
Gotta love the Friday 13th formula 😀
Great tips from you all! Thanks a lot for sharing! bsamson, particularly you helped me on a terribly annoying task. 🙂
(BTW, Chandoo, it's not exactly "Find if a range is normally distributed" what my suggestion does. It checks if two proportions are statistically different. I probably gave you a bad explanation on twitter, but it'd be probably better if you fix it here... 🙂 )
Great compilation Chandoo
For the "Clean your text before you lookup"
=VLOOKUP(CLEAN(TRIM(E20)),F5:G18,2,0)
I would like to share a method to convert a number-stored-as-text before you lookup:
=VLOOKUP(E20+0,F5:G18,2,0)
@Peder, yeah, I loved that formula
@Aires: Sorry, I misunderstood your formula. Corrected the heading now.
@John.. that is a cool tip.
Hey Chandoo,
That p-value formula is really great for a statistics person like me.
What a p-value essentially is, is the probability that the results obtained from a statistical test aren't valid. So for example, if my p value is .05, there's a 5% probability that my results are wrong.
You can play with this if you install the Data Analysis Toolpak (which will perform some statistical tests for you AND provide the P Value.)
Let's say for example I've got two weeks of data (separated into columns) with the number of hours worked per day. I want to find out if the total number of hours I worked in week two were really all the different than week one.
Week1 Week2
10 11
12 9
9 10
7 8
5 8
Go to Data > Data Analysis > T-Test Assuming Unequal Variances > OK
In the Variable 1 Box, select the range of data for week 1.
In the Variable 2 Box, select the range of data for week 2.
Check "Labels"
In the Alpha box, select a value (in percentage terms) for how tolerant you are of error.
.05 is the general standard; that is to say I am willing to accept a 95% level of confidence that my result is accuarate.
Select a range output.
Excel calculates a number of results: Average (mean) for each week's data, etc.
You'll notice however that there are two P Values; one-tail and two-tail. (one tail tests are for > or .05), the number of hours I worked in week two is statistically equivalent to the number of hours I worked in week one.
So here’s a way you might want to use this. You put up a new entry on your blog. You think it’s the best entry ever! So you pull your webstats for this week and compare it to last week. You gather data for each week on the length of time a visitor spends on your website. The question you’re trying to prove statistically is whether there’s an average increase in the amount of time spent on your website this week as compared to last week (as a result of your fancy new blog post). You can run the same statistical test I illustrated above to find out. Incidentally, it matters very little to the stat test whether the quantity of visitors differs or not.
Anyhow, the Data Analysis toolpack doesn't perform a lot of stat tests that folks like me would like to have access to. In those cases I have to either use different software, or write some very complicated mathematical formulas. Having this p-value formula makes my life a LOT easier!
Thanks!
Eric~
Fantastic stuf..One line explanation is cool.
Thanks to all the contributors
OS
Take FirstName, MI, LastName in access (you can fix it to work in excel) capitalize first letter of each and lowercase the rest and add ". " if MI exists then same for last name:
Full Name: Format(Left([FirstName],1),">") & Format(Right([FirstName]),Len([FirstName])-1),"") & ". ","") & Format(Left([LastName],1),">") & Format(Right([LastName],Len([LastName])-1),"<")
I teach excel, access, etc etc for a living and i have my access students build this formula one step at a time from the inside out to show how formulas can be made even if it looks complicated. Yes I know I could just do IsNull([MI]) and reverse the order in the Iif() function but the point here is to nest as many functions as possible one by one (also I illustrate how it will fail without the Not() as it is)
Extract the month from a date
The easiest formula for this is =MONTH(a1)
It will return a 1 for January, 2 for February etc.
if in a column we write the value of total person for eg. 10 if we spent 1.33 paise each person then how we get total amount in next column and the result will in round form plzzzzz solve my problem sir................... thank u
@Anjali
If the value 10 is in B2 and 1.33 paise is in C2 the formula in D2 could be =B2*C2
If the values are a column of values you can copy the formula down by copy/paste or drag the small black handle at the bottom right corner of cell D2
kindly share with me new forumulas.
How to convert a figure like 870.70 into 870 but 871.70 into 880 using excel formula ? Please help.