The article compares different methods used to evaluate how uncomfortable certain working postures are for people. The researchers looked at 42 different postures commonly seen in car assembly lines and had 17 men rate how uncomfortable they felt in each posture. They then compared these ratings to the results from three different observational methods. The study found that the observational methods gave different stress levels for the same postures, especially for those that were rated as very uncomfortable. This suggests that the choice of evaluation method should depend on the specific situation, and that there are areas where these methods can be improved.