That does sounds a bit tricky, but what I'm attempting is not really all that complex. I'm going through the code right now and my thought at this point is that I may have gotten a bit confused with the QAbstractModel class documentation. The requirement for the dataChanged signal indicates two QModelIndex values need to be passed to the function, one for the top left corner of the data area and one for the top right. Since I'm only addressing one point (or cell), I was passing the same index value in both arguments. I'm in the process of verifying if that is a valid or invalid way of addressing just one point right now.