Explaining the unbiased creation of treatment comparison groups and blinded outcome assessment
A class were given coloured sweets and asked to design an experiment to find out whether red sweets helped children to think more quickly.Key Concepts addressed:
A class of 11-year-old children in Norway were given a supply of coloured sweets, and asked to design an experiment to find out whether red sweets helped children to think more quickly. The children pointed out that an experiment comparing the effects of red and non-red sweets would need to hide the colour of sweets from the participants: knowledge of the sweet colour might otherwise affect judgments about thinking speed. They understood the need to try to reduce the biases of the observers.