What is ICSEA?
Throughout the site, you may have seen a figure called ICSEA. What exactly is it, and how should it be interpreted?
ICSEA stands for Index of Community, Socio-Educational Advantage. This index is calculated from the following factors:
% of Indigenous Students
A higher ICSEA value means a higher education advantage of students going to the school, and vice versa. The average of ICSEA is set at 1000.
Besides the actual ICSEA value, the website also uses ICSEA Percentile. It translates the numerical value into percentile (1-100%) for easier comparison. An ICSEA value of 1,000 would be translated to an ICSEA Percentile of 50%. The highest ICSEA value in Australia would be at 100%.
Better ICSEA means better school?
Short answer is No.
A higher ICSEA means the students have more education advantage than others, but this is not an indication on how well their students has performed academically. That said, it generally has a positive correlation between ICSEA and academic achievements.
At the bottom of this post is an interactive box and whisker chart which shows the academic rating distribution for similar schools (grouped by every 5% of ICSEA percentile). The median of the rating (the line between the two shaded rectangles) has a positive correlation to the ICSEA.
Schools on the upper left area means they perform well above average compare to schools with similar ICSEA value. On the contrary, schools on the lower right area perform well below average.
There are numerous factors that contribute to a school falls into better / average / worse area, for example:
School size - smaller schools with less students tend fluctuate more than larger schools due to smaller sample size. For a small school, a few high-achieving students can ramp up the rating.
School effort - the teaching staffs putting extra efforts to cater for different students' needs may lead to their above average results.
Student composition - some schools cater for students with special educational needs (SEN). This would resulted in the achievement being shown as "worse", but it does not mean these schools are under-performing.
Parents' influence - when a significant portion of a school's parents are determined to train their children for better academic achievements (e.g. tuition classes, intensive homework and exercises, etc.), the rating may ramp up - and not necessarily due to school's teaching. This is especially true for high ICSEA schools, as their family are usually more wealthy and well-educated.
How to interpreting a box and whisker chart? (click the arrow on the left to expand)
At first sight, a box and whisker chart may be daunting to understand. No worries! In this section you will get to know the basics.
This chart is useful to show the distribution and spread of a group of numerical data. The key elements are:
Median (50th percentile) - The boundary between the two boxes. Assume there are 100 schools within the group, median would be the rating of the 50th ranked school. Note: Median is not average. It simply takes the rating from the 50th ranked school. It is not calculated from the average ratings of all schools in the group.
First quartile (25th percentile) - The bottom boundary of the lower box. Using the same assumption as above, it would be the rating of the 75th ranked school (since it is counting from the lowest rating).
Third quartile (75th percentile) - The top boundary of the upper box. It would be the 25th ranked school out of 100 schools.
IQR (interquartile range) - instead of confusing you with statistical terms, think of an area which cover the majority of distribution outside of the boxes.
Outliers - Data points which falls outside of the whiskers. They are either well above or well below the norm.
Points - Each point represents the rating of a school. In the interactive chart below, you can select any point and reveal the school details.
Next, let's understand what is ICSEA Percentile (bin).
Here, all schools in Australia are divided into 20 groups based on their ICSEA value. Each group would contains approximately 5% of all schools. The lowest group (0) contains schools with the lowest 5% (i.e. 0-4.99%) of ICSEA value, while the highest group (95) contains the highest 5% (95-100%). Schools within each group are considered to have similar educational advantage (or disadvantage).
By combining the ICSEA Percentile (bin) with box and whisker chart, it shows the distribution of school ratings for similar schools.
To learn more in-depth details, please visit this article on Wikipedia.
Hover / touch on a point on the chart below to reveal details of individual schools.