✓/✗ Validity - The study had detailed documentation on the standardised procedure and good use of controls such as the three main phases, briefing of the observers to use the same procedure and the methods to record the boys' behaviour. This meant all the boys experienced the same experimental conditions and increases internal validity. Sherif claimed that, by using several data collection methods (e.g. observing, tape recording, tests, quantitative and qualitative data) that agreed with eachother to be accurate, the validity of the results was high. There was no control group meaning the ability to draw a valid cause and effect was reduced as there was no baseline to compare the experimental results to. The study has ecological validity as the boys were ata summer camp, typical of what they may have done. The specially created tasks (e.g. unblocking a vandalised water pipe) seemed real to the boys, meaning their behaviour was reflective of real life and demand characteristics were minimised. This increases mundane realism due to task validity.