Selecting Colours in PowerPoint

Sometimes at Group Dynamics, we're asked to check the colours in a PowerPoint presentation for accessibility with regards to colour perception deficiency, or colour blindness as it is more commonly known. Whereas this is something you should generally not have to worry too much about if you are following a professionally designed template, if you are creating your own template from scratch, whether for audience voting or not, it is worth spending a little time to avoid excluding a percentage of your audience. To help, here are some examples and links to further information you might find useful.

Approximately 1 in 12 people have some kind of colour perception deficiency. Try to avoid using colour contrast or colour schemes to convey information and you should also take into account that there are different types of colour blindness, and that they are sensitive to differences in material (ie. paper, computer screens etc).

Colours as perceived by a person with no colour deficiency.

 

Colours as perceived by a person with protanopia.

 

Colours as perceived by a person with deuteranopia.

 

Colours as perceived by a person with tritanopia (very rare).

 

For more info on colour blindness, take a look at this Wikipedia article.

Click here for a handy tool which can show you how specific
RGB colours are perceived in eight types of colour blindness.

Click here for another handy tool which allows you to upload
an image to see how it will be perceived by colour blind people.

 

 

Names in Excel

Although our audience response software, PowerQ, runs inside PowerPoint, we are often asked to perform analysis on the voting data for a myriad of reasons. This naturally brings us into constant contact with Excel and its extremely powerful set of formulas.*

What we quickly come up against is a sheet full of rows and rows of data waiting to be analysed. Many formulas use ranges and it's very easy to lose track of which range applies to what. It gets even more complex if you move the formula around as the range is likely to change too.

Fortunately, Excel provides us with a simple yet powerful solution. All we need to do is select a particular range, and then type in a name into the Names dropdown box at the top left of the screen. But how does this help?

Well, let's say our audience response system has created a table with the scores for a particular round of a quiz. What we might want to do is find the spread of scores, in other words, the difference between the maximum and minimum number in the scores.

If our scores start in cell B3 and end in cell B102, traditionally we would write something like this:

=max(b3:b102)-min(b3:b102)

Ok while we still can remember what it refers to, but a few more analyses later and we might be wondering!

So, instead, what we can do is select the range b3 to b102 and then type 'Scores' into the helpfully titled 'Name Box' in Excel. And now our formula will read:

=max(Scores)-min(Scores)

It makes the whole business so much easier!

 

 

 

 

*Should it be 'formulas' or 'formulae'? The pedant in me says the latter, but it just sounds a little pompous!