A recent answer on StackExchange linked to a blog post claiming that:
Research suggests that in an eight-hour day, the average worker is only productive for two hours and 53 minutes.
According to the Bureau of Labor Statistics, the average American works 8.8 hours every day. Yet a study of nearly 2,000 full-time office workers revealed that most people aren't working for most of the time they're at work.
Following the link given in the blog post, I find just another post writing about the study without directly linking to it. It claims:
The study, conducted by www.vouchercloud.com, polled 1,989 UK office workers all aged over 18 as part of research into the online habits and productivity of workers across the nation. All respondents currently worked full-time in an office role.
What makes me extremely sceptical is their method of data collection.
Respondents who admitted that they were guilty of ‘at work distractions’ were asked how long they believed they spent on each one during the course of a working day, which revealed the following averages when taken from all respondents...
This looks more like an online survey than an actual study to me, much less a scientifically sound study. In addition to that, it seems the authors drew the wrong conclusion from the data and ignored those workers who claim they can work a full 8 hours without distractions.
My question is:
Is there credible proof that the average office worker is only productive for 3 hours a day?
Is there a study that recorded office productivity by actually observing employee behavior?
To keep the scope of possible answers small, I'd like to concentrate on office workers only. Studies that concentrate on a specific sector of the industry are acceptable.
Please note: I'm not interested in weekly productivity. There are several studies that examine productivity based on weekly working time. I'm only interested in the claim that the average office worker isn't productive more than half of the day.