Apple’s study focused at the wrong level of work. Pasting spreadsheet cells is not a user task, it’s an operation at a low interaction level. More meaningful productivity has to be measured at a higher level, where users string together a sequence of operations to achieve their real-world goals.
With spreadsheets, for example, one of my recent tasks was to update a conference budget to reflect the option of adding another day of seminars. Such a task might well involve operations in which users would identify the cells containing an existing seminar day’s expenses; copy these cells; paste them into a new day’s area; and update the new cells to reflect the differences between the two days.
True worker productivity in this example would be determined by how quickly users could arrive at the new budget. Interestingly, a bigger screen would benefit many of the task’s other operations. For example, it’s faster to identify a big budget’s relevant elements when you can see all of them at once. It’s also faster to compare two potential budgets if you can see both of them together in one view. I don’t question that bigger monitors are better, I’m simply pointing out that we can’t trust Apple’s study to estimate the magnitude of the benefits. …
He then suggests number of ways to estimate productivity improvements. One important aspect is not telling users how to do the representative tasks and observe their real behavior.
It’s a good article to understand and think about quantifying productivity on computing related tasks.
Productivity and Screen Size – [Jakob Nielsen's Alertbox]