Very simple, yet tricky question about representing data in bar charts, any opinions?

P

parsec2011

Guest
#1
Dear readers,

I have conducted analysis on a open answer question about quality of service delivered to customers. Currently, I am in the process of making bar charts, however, something easy becomes tricky when analyzing big datasets. Since the amount of data that I processed was quite large, the coding of the data resulted in 20-30 categories of situations. It would be awful to create a chart with 20-30 bars.

My question: In your opinion, what is the maximum bars I should put in a bar chart, histogram, or "slices" in a pie chart to convey clear and easy to understand information?

Many thanks for your input,

Ramon
 
#2
Re: Very simple, yet tricky question about representing data in bar charts, any opini

not sure that you can quantify it to a number, but I wouldn't put too many of them, that's for sure.

and if you present your results, I often find it better to use bar charts over pie charts. since your data is qualitative and not quantitative, you can't use a histogram.
 
P

parsec2011

Guest
#3
Re: Very simple, yet tricky question about representing data in bar charts, any opini

To NN_ Stat:

Thanks a lot!

Indeed, no histograms in qualitative analysis.

I have checked my research books, and the most populated charts hold 6-10 bars, thats what I will try to do.

In addition, for each of the 30 categories, I will measure the percent from total replies in the sample, along with their respective standard error. For those getting +/- 5 SE, I will create an "Other category" that will effectively "incorporate" the least-important responses. Alternatively, my "Other category" may include all answer categories that get less than 10% of the total responses. I believe the first option is better. The main objective is to reduce the bias caused by arbitrarily assigning "low represented categories" and dumping them into an other group.

Qualitative and quantitative data aren't always easy to mix. :)

Ramon
 

Dason

Ambassador to the humans
#4
Re: Question about maximum bars to display on a chart

Well you could aggregate some of the smaller groups if there is a natural way to combine them. You could also looking into pareto charts. I would shy away from pie graphs if possible.
 

Dason

Ambassador to the humans
#5
Re: Very simple, yet tricky question about representing data in bar charts, any opini

Also don't post a thread in more than one location.
 
P

parsec2011

Guest
#6
Re: Very simple, yet tricky question about representing data in bar charts, any opini

@ Dason:

Thanks, I wasn't familiar to the pareto concept although that is what I am in fact using for my report.
I also believe the position of the bars in an important factor. I am using a vertical top-down axis instead of the more commonly used horizontal left-right one.
In my case (because of the many categories I have), it is easier to read, and visualize the data.

Sorry for the duplicate post, am still new to the forum.

Ramon