Matrix question
Also called grid question, battery
Several statements sharing one set of answer columns, shown as a grid.
A matrix uses one scale for several statements. Long grids can be difficult to answer on a phone, so preview the layout and consider splitting them into smaller groups.
Count each row when estimating respondent effort. Analyze rows separately unless you have a reason to combine them into a scale.
Keep matrices short, keep every row on the same scale in the same direction, and put the rows that matter most at the top: attention falls measurably down a long grid.
Where it goes wrong
Counting a matrix as one question when estimating length. Ten rows at six seconds each is a minute, and the estimate that called it one question is out by a factor of ten.