Asch's conformity study found that group size and the influence of confederates changed the belief and behaviour of the naive participant as 75 percent of participants conformed to the wrong answer in the line length task on at least one trial. However, these findings can be evaluated since, in a replication on Yorkshire engineering students, by Perrin and Spencer, it was found that the study's findings lacked temporal validity. This is since only 1/396 trials conformed to the wrong answer. Hence, a weakness is that the findings cannot be generalised to all time settings and in that way, are flawed.