Constant Sum Analysis.

Constant Sum allows respondents to assign a numeric value to each choice in your question (Constant Sum: Choice) OR to each choice in your statements (Constant Sum: Matrix), e.g.

1: Constant Sum: Choice - assign a numeric value to each choice in your question

2: Constant Sum: Matrix - assign a numeric value to each choice in your statements

This is one of the most complex question types to analyse in Glow as we have to analyse numeric answers in choices, statements, loops, and across filters.

Constant Sum Analysis

In this article, we'll show you how to analyse:

Constant Sum: Choice
Constant Sum: Matrix

Using these 2 Values:

Average
Sum

But before we see how to analyse constant sum, let's 1st inspect our constant sum responses.

Responses

There are 3 answer types in constant sum:

>0 or <0 (light purple)
0 (medium purple)
Blanks (dark purple) - means respondent didn't see that choice or statement.

Glow's analysis calculations always excludes 0s and Blanks and only includes answers that are >0 or <0.

However, it should be noted that:

1/2 the time it makes more sense to include 0s
But the other 1/2 it's better to exclude 0s.

But there's no option (yet) in the platform to include 0s in constant sum analysis so if you need that, you'll have to do those calculations yourself off platform, like I did below in Rows 14, 17, and 20.

Constant Sum: Choice

Let's now analyse Q2 (Constant Sum: Choice), for Restaurant A with answers 0, 5, 3, 2, 4, 4, 0, 4, 10, 5 (per Column J above):

the Base is n=8
the Sum is 5+3+2+4+4+4+10+5 = 37
the Average is Sum: 37 / n: 8 = 4.6

For Restaurant DEF with answers 0, 4, 1, 0, 0, 4, 3, 7, 6, 4 (per Column K above):

the Base is n=7
the Sum is 4+1+4+3+7+6+4 = 29
the Average is Sum: 29 / n: 7 = 4.1

Note again that 0s are excluded from analysis calculations.

Though in this case, that's precisely what we want!

You'll see the base counts in the Total (n) column at the far right of your table.

Use the Values slot (above your table to the left) to toggle between Sum and Average.

To crosstab your results, simply click '+Filter' in your table columns and add cross filters (e.g. Male and Female) to your chart and table.

Constant Sum: Choice analysis complete! 🎉

Constant Sum: Matrix

Let's lastly analyse Q3 (Constant Sum: Matrix) for Restaurant ABC (Columns Q to V in Responses). We can see:

Breakfast (2, 1, 1, 3, 0, 0, 3, 0) - Sum: 10 / n:5 = 2.0
Morning Snack (2, 0, 0, 0, 0, 0, 1, 0) - Sum: 3 / n:2 = 1.5
Lunch (1, 1, 0, 1, 0, 3, 3, 3) - Sum: 12 / n:6 = 2.0
Afternoon Snack (0, 0, 0, 0, 0, 0, 1, 1) - Sum: 2 / n:2 = 1.0
Dinner (0, 1, 1, 0, 4, 1, 1, 1) - Sum: 9 / n:6 = 1.5
Post dinner / late night (0, 0, 0. 0, 0, 0, 1, 0) - Sum: 1 / n:1 = 1.0
Sum of Restaurant ABC Averages = 9.0

Likewise, for Restaurant DEF (Columns W to AB in Responses):

Breakfast (0, 0, 4, 0, 0, 0, 0) - Sum: 4 / n:1 = 4.0
Morning Snack (2, 1, 0, 0, 0, 0, 0) - Sum: 3 / n:2 = 1.5
Lunch (0, 0, 0, 3, 0, 5, 1) - Sum: 9 / n:3 = 3.0
Afternoon Snack (0, 0, 0, 0, 0, 1, 0) - Sum: 1 / n:1 = 1.0
Dinner (0, 0, 0, 0, 6, 0, 3) - Sum: 9 / n:2 = 4.5
Post dinner / late night (2, 0, 0, 0, 1, 0, 0) - Sum: 3 / n:2 = 1.5
Sum of Restaurant DEF Averages = 15.5

Again, note that 0s have been excluded from our analysis at Q3, per the current calculation settings.

But had we instead included 0s, note that we would have seen perfect alignment between Q2 averages and Q3 sum of averages.

E.g. Q3 Averages for Restaurant DEF when including 0's:

Breakfast (0, 0, 4, 0, 0, 0, 0) - Sum: 4 / n:7 = 0.6
Morning Snack (2, 1, 0, 0, 0, 0, 0) - Sum: 3 / n:7 = 0.4
Lunch (0, 0, 0, 3, 0, 5, 1) - Sum: 9 / n:7 = 1.3
Afternoon Snack (0, 0, 0, 0, 0, 1, 0) - Sum: 1 / n:7 = 0.1
Dinner (0, 0, 0, 0, 6, 0, 3) - Sum: 9 / n:7 = 1.3
Post dinner / late night (2, 0, 0, 0, 1, 0, 0) - Sum: 3 / n:7 = 0.4
Sum of Restaurant DEF Averages = 4.1 incl. 0s (vs. 15.5 excl. 0s)

This would align perfectly with Avg of 4.1 for Restaurant DEF at Q2.

So, 1/2 the time, exclude 0s is best (e.g. Q2). But the other 1/2, include 0s makes more sense (Q3).

So, there will likely be a checkbox in the future in each constant sum view to include 0s.

But in the meantime, please note that 0s are excluded by default from constant sum analysis!

Constant Sum analysis done! 🎉