If direct observation is ineffective or not available, people will then turn to comparable others for validation.[24] In other words, social comparison theory predicts that social reality testing will arise when physical reality testing yields uncertainty. The Asch conformity experiments demonstrate that uncertainty can arise as an outcome of social reality testing. More broadly, this inconsistency has been used to support the position that the theoretical distinction between social reality testing and physical reality testing is untenable.[14][5][25][26]