Year ago when Lucent (AT&T) manufacturing was outsourced and my job was gone, I applied for a mid level engineering job at a component manufacturer that I had used often. At one point in the interview, the inhouse HR guy had me assembling washers and nuts onto bolts following some simple verbal instructions. When I questioned why - he said everybody gets this test. Oh boy.
I can understand the exercise. At a previous job, I had to hand-write a letter to one of the owners expressing my interest in the position and company.
I was told what he was looking for was the ability to write coherent sentences, spelling and original thoughts. He turned out to be a mammoth AH, but I respected the request.
I would do the same, but I would most likely adjust the pay rate - higher for higher performers of the testing, lower or rescind any offers for poor performers.