A researcher investigated the impact of blue-light filtering glasses on sleep latency (the time taken to fall asleep). A sample of 12 participants spent one week wearing blue-light filtering glasses for 2 hours before bed (Condition A) and another week wearing clear, non-filtering glasses (Condition B). The order of conditions was counterbalanced. The mean sleep latency in minutes was recorded for each participant under both conditions.

Table 1: Mean sleep latency (minutes) for the two conditions

	Condition A (Blue-light filtering)	Condition B (Clear glasses)
Mean sleep latency (minutes)	22.4	38.6

Explain which statistical test the researcher could have used to analyse these data.

Table 1: Mean sleep latency (minutes) for the two conditions

	Condition A (Blue-light filtering)	Condition B (Clear glasses)
Mean sleep latency (minutes)	22.4	38.6

Explain which statistical test the researcher could have used to analyse these data.

Methods

Question 13

Table 1: Mean sleep latency (minutes) for the two conditions

Markscheme

Methods

Question 13

Table 1: Mean sleep latency (minutes) for the two conditions

Markscheme

Methods

Question 13

Table 1: Mean sleep latency (minutes) for the two conditions

Methods Questions

Methods

Question 13

Table 1: Mean sleep latency (minutes) for the two conditions

Methods Questions