In fact how can the working effectiveness of IT workers be properly measured? Personally I'm not sure if there is any measurement approach out there, but I'm sure that will not be a straight forward method.
Sometimes I realized that people used to minimize or close their web browser or switch to other windows while other people especially their bosses passing by their seats. I can understand why they do so because I also did the same thing when reading some sensitive information during office hours. If you are working in IT line, I think you probably know that what I'm talking about. If you aren't, here is the reason.
Boss always think that you have nothing to do or you are not focusing on your works if you are surfing web during office hours.
Now the question is, can the behavior of the employees in the offices becomes the source for employers to assess employees' performance?
Imagine you are a boss, and your employee is currently doing nothing, what is the first thing you'd want to find out? Apparently, I'd want to know the progress of the tasks which have been assigned to the employee. Secondly, what if the employee had got the tasks done? Switch back to your current role (you are no longer a boss), until now, should we put the blames on the employee for being idle or question the boss for the unjustifiable task assignment?
Some independant workers might stand up and shout "we should always take initiative to approach for more tasks after we had completed our work!". Ask for more tasks, right, it is good if you are working in government department. But, in IT industry, we have something called "development schedule". Say we are having 10 tasks which got to be finished in 5 days time, and we are having 5 programmers in the team. What is the point of having the schedule in the first place if the programmer who can work fast can request to take up the tasks of other programmers? And, yes, the fast programmer might have no time to read web after taking the slow programmers' tasks. But, should the slow programmer be blamed for surfing in the fifth day after finishing 1 task?
So, to the IT managers out there, kindly don't assign task to the employee who are surfing web, which you should have done the proper task schedule at the beginning. To the programmers, try your best to tell your managers the exact time needed for given tasks, or you will be blamed for surfing web or making your slow teamates to be blamed.