Figure CWF4.2 shows the average writing scores for this group and for year four students in Tuvalu in previous PILNA cycles. The score in 2021 (470.56, SD = 36.57) was higher than in 2015 (387.69, SD = 90.98) and 2018 (408.12, SD = 87.05). The standard deviation for the average year four writing scores in 2021 (37.57) was lower than in 2015 (90.98) and 2018 (87.05). This shows that the spread of writing scores in 2021 was narrower than in previous PILNA cycles.

Standard deviation shows how close data points are to the average. A lower standard deviation means that data points are, overall, closer to the average; a higher standard deviation means that data points are, overall, further away from the average.