Repeated measures

• Participants are all in one group and the same group takes part in all conditions of the experiment
• A strength of repeated measures design is that the participants take part in all the conditions. As a result, there are no individual differences between conditions that may impact the results. This ensures that the differences between the conditions are due to IV manipulation rather than existing differences between participants. Thus increasing validity
• A weakness of repeated measures is that since participants partake in all conditions, there may be order effects. This is when a participants performance in the latter conditions may be worse due to boredom or fatigue. As such, order effects may impact participants performance and affect the results so they'll no longer be due to IV manipulation. Thus decreasing the validity
• A weakness of repeated measures is that because participants partake in all conditions, they may realise the aim of the experiment. This may lead to demand characteristics. These are when a participant changes their behaviour to suit or refute the aim of the research. This leads to participants displaying unnatural behaviour which will lead to false data. Thus decreasing the validity of findings and conclusions drawn