The most unbiased test of a new prediction technique is when it is applied to a protein without prior knowledge of its three-dimensional structure. Protein-Tyrosine Phosphatase is an important enzyme which controls how active other enzymes in cells are. We made a prediction of the order and position of the helices and strands in its structure. When the structure had been solved we compared it to our prediction. More than 75% of the amino acids had been predicted to be in the right kind of structure (green). In some cases we had got the length of the structures wrong or had missed out small structures which are not an important part of the three dimensional structure (grey). Only one serious mistake was made - the tip of one helix was predicted as a strand (red).