I used to test block patterns for Marcia at QUILTER'S CACHE
Marcia offered her patterns at no cost but was conscientious enough to have volunteers test all of her block patterns to check for errors before posting on her website.
On the other hand, we have quilt magazines that publish patterns that are apparently not proofread and/or tested before publishing. It is a constant irritant to me when I run across mistakes. I realize mistakes happen, but it has got to the point that I get out my calculator and graph paper to check patterns before I start cutting.
I am making a quilt for my husband from a pattern in a magazine from last year. The instructions have all of these cuts from different colors of fabrics. And it doesn't give the size of the finished blocks so you have to trust that the cutting instructions are correct. Part of the top is from a panel, and then there are pieced blocks in between. These blocks had templates, and the five blocks were supposed to fit along the bottom of this part of the panel.
None of the blocks in this top are easily pieced.. there are 2 pieced houses, pieced saws, hammers, flying geese, the inside border is pieced diamonds... all of which probably won't fit unless I adjust the measurements because the innermost design area has had to be adjusted to work, and wont be the right size. Needless to say.. good thing his birthday is in July, because Christmas is out.