Comments on: How Many Decimal Places Are Helpful?

By: Ann K. Emery | How to Visualize Workshop Evaluation Results

Ann K. Emery | How to Visualize Workshop Evaluation Results — Tue, 20 Mar 2018 15:26:31 +0000

[…] So many decimal places. I would never change my workshop approach because a tool told me that 88.89% of people answered a certain way. That’s 89%. I’m the audience for this report. I know exactly what’s useful for me and what isn’t. Decimals won’t change my life. […]

By: gf

gf — Wed, 23 Sep 2015 20:19:04 +0000

Similar to the ‘issue that requires action’ comment. Places where the decimal can be a significant amount of the over all number. The difference between 2.6 and 2.9 is a large percentage swing of the overall value, once again masking a difference in the data that could cause users to make a different decision.

By: Dave Paradi

Dave Paradi — Wed, 23 Sep 2015 15:07:05 +0000

In reply to Dave Paradi.

Ann,
I had an example from a client last year where they included six decimal places in every cell in the spreadsheet simply because Excel can do it. They didn’t realize how crazy it was until I asked them about it. Just because the software can do it doesn’t mean you should let it do it.
I agree that presenters should make conscious decisions. Don’t abdicate decision making by accepting whatever the program default is. Have a reason for each decision.
Dave

By: Ann K. Emery

Ann K. Emery — Tue, 22 Sep 2015 20:04:13 +0000

In reply to Sheila B Robinson, Ed. D. Yes! I'm putting your giant slalom example in my "fancy gadget" category. Imagine if our research and evaluation measurements were that precise...!

By: Sheila B Robinson, Ed. D

Sheila B Robinson, Ed. D — Tue, 22 Sep 2015 20:02:09 +0000

I rarely use decimal places unless a greater degree of precision is needed for a specific decision, or the particular data type warrants it, but it’s certainly not often! A place where I would use decimal places? Graphing the performances at the Giant Slalom during the Winter Olympics! 😉 I’m always amazed that one-tenth of a second can separate the 1st place winner from the 2nd.

By: Ann K. Emery

Ann K. Emery — Tue, 22 Sep 2015 18:48:52 +0000

In reply to Dave Paradi.

Dave – thanks for sharing.
“An issue that requires action” – yes! Great litmus test for determining whether decimal places will add value or not.
I love your logic and careful thought process behind these decisions. I often see several decimals included in graphs simply because the analyst’s software program included those decimals places by default.
Three cheers for purposeful design.