Merged Rows

When an attribute doesn't apply to a product concept, it is shown as "blank".  This may be just fine for certain kinds of alternative-specific design studies.  However, there are other instances in which too many blanks would appear in the choice task, leading to poor readability of the product concepts.  In those cases, the ability to Merge Rows is provided.

As a simple example, let's imagine that depending on whether a computer is a desktop or a laptop, we want to test a different range of processor speeds.  We create two attributes for processor speed:

Laptop_Processor_Speed:

1.5 GHz

2 GHz

3 GHz

Desktop_Processor_Speed:

2 GHz

3 GHz

4 GHz

Without doing anything special, product concepts would appear in the questionnaire similar to the following pair of concepts:

But, we can merge the last two rows and replace the attribute text in the first column with something more generic, such as Processor Speed, resulting in the following display:

The experimental design has not changed (there still are two separate attributes for Processor Speed, one for desktop and the other for laptop); we've just changed the way the information is displayed on the screen for the respondent.