Percentile/SFO Comparison Charts Data and Evaluation Division Feb 2008
Purpose of presentation To explain to schools the replacement for the Like School Group approach, the Percentile/SFO Comparison Charts.
Topics • The Problem • The Previous Solution (LSGs) • Alternatives Considered • Percentile/SFO Comparison Charts
The Problem How does my school’s student achievement score compare to other schools, given that my school is “different” to the average school?
The Previous Solution - LSGs • “Like” school groups (LSG) commenced in 1996 • Created so schools could compare their performance to “similar schools” • 9 LSGs based on two measures; • EMA/Youth Allowance: proportion of students in school in receipt of EMA or Youth Allowance • LBOTE: proportion of students from a language background other than English
LSG chart • Good acceptance overall, but weaknesses are now apparent • Weaknesses include: • Schools close to a boundary (unfairly compared to all schools in LSG) • EMA/Youth Allowance data no longer available • LSGs are of unequal size (no. of schools in LSG4 is almost 10x that in LSG3)
Alternatives considered 1) Like School Sphere • For each school, compare results to performance of 19 nearest schools (in terms of SFO and maybe LBOTE, enrolment) • Gets extremely complicated statistically 2) Percentile/SFO Comparison Charts
Student Family Occupation (SFO) densities • Indicator of socio-economic status • SFO accounts for 38% of variance in student achievement • LBOTE only accounts for an additional 5% • Used in Student Resource Package • 4 years of SFO data (2004-2007)
2005 SFOs for primary & pri/sec schoolssorted from highest to lowest socio-economic status (SES) Lowest SES 22nd percentile Highest SES Highest SES
78% of schools have a student population from a higher socio-economic background 22% of schools have a student population from a lower socio-economic background Nameless Primary School
2005 AIM Year 3 Reading mean scoressorted from lowest to highest score Lowest scoring school Highest scoring school
Nameless Primary School If socio-economic status, as measured by SFO, was the sole determinant of student achievement, you’d expect the school’s achievement percentile to be in the same vicinity as the SFO percentile. 20% of schools have a lower AIM score
2005 SFOs for primary & pri/sec schools sorted from highest to lowest socio-economic status (SES) Lowest SES Highest SES Highest SES
Nameless Primary School The (up to) 20% of schools that are most like this school in terms of SFO.
Staff Opinion Survey Parent Opinion Survey Student (Attitudes to School) Survey
Value-add? No • Not an attempt at value-add • Simply is what it is • If SFO was the sole determinant of student achievement, a school’s student achievement percentile would be within the “vicinity” of its SFO percentile. If it’s above (or below), the school could hypothesise why.
Percentile/SFO Comparison Charts Principles behind • Use Student Family Occupation (SFO) only as best predictor of student achievement • Examine student achievement and SFO percentiles together • Keep it simple • Use lots of data, over time, across strands (don’t rely on any one bit of data) • Combine the data with the school context to get the full story