Despite widespread use of effect sizes across industries as a standardized measure of impact, effect size calculations remain one of the most incorrectly applied and misinterpreted statistics. An effect size is nothing more than a standardized comparison, or “effect” , that captures the difference between an average value and a meaningful comparison in the metric of standard deviation.
The fundamental purpose of setting school improvement goals is to assess the effectiveness of improvement efforts. The utility of the school improvement process rests on the inferences one can draw from meeting a goal. For example, a typical school improvement goal may be â€œincrease the percentage of students meeting standards in grade 4 reading by 5%. While this type of goal is specific and concise, the results will provide little to no information as to the effectiveness of improvement efforts. Why? Because increasing grade 4 reading by 5% is likely an arbitrary goal that is unrelated to school performance and not evidence-based.