How do I add a new continuous factor to a DoE via design augmentation?

[#1]

I am sure I used to be able to do this, but now when I try to add a new continuous factor to an existing DoE via the Augment Design Platform I am not having success.

What  I would have done in the past is add my new factor as a column on the existing datatable (all values constant -as it wasn't varied in the initial experiment then upon opening the Augmentation platform, I would have added all desired factor columns (inc. the new one) to the factor box and my responses in the response box. However when I do this my new factor shows as "constant" in the factor table and I am not able to switch it to continuous, and I can neither change the values boxes to make it variable nor include it as a term in my model.

I have done this before successfully,  and I am sure the solution is simple but I can' t work out what I am doing wrong in this case....

Any help would be appreciated!

[#2 · Accepted solution]

I am not sure what changed, but this method works. It helps to add column properties to distinguish the new factor column. I added X4 to a design originally for X1-X3.

I selected the new column (X4) in the data table, clicked Columns menu and selected Column Info. Then I added three column properties for DOE.

After those additions, I followed the same procedure as the one that you used.

[#3]

Thank you Mark that got me what I needed, - honestly not sure if something had changed, or if I had just overlooked the initial stage of setting the column up properly!