Attachment A Cronbach alpha formula and reliabilities NAPLAN 2008 2012 – – Date: 28 June 2013 Formula The formula for computing the NAPLAN reliability is the Cronbach’s Coefficient Alpha. Cronbach alpha reliabilities NAPLAN 2008 2012 – – In relation to NAPLAN 2008 - 2012, the table below provides the Cronbach alpha reliabilities of each test. Note that the alpha coefficient for Writing is computed using pooled data from all grades. Calendar Year Reading Writing Spelling Grammar Numeracy Year Level and Punctuation 3 0.89 0.92 0.78 0.87 5 0.89 0.91 0.80 0.88 2008 0.94 7 0.88 0.90 0.77 0.93 9 0.88 0.91 0.78 0.92 3 0.88 0.92 0.87 0.84 5 0.87 0.92 0.84 0.87 2009 0.93 7 0.89 0.91 0.83 0.93 9 0.88 0.90 0.79 0.92 3 0.86 0.93 0.83 0.86 5 0.85 0.92 0.75 0.87 2010 0.94 7 0.90 0.93 0.71 0.93 9 0.89 0.90 0.79 0.91 3 0.87 0.93 0.82 0.87 5 0.87 0.92 0.82 0.87 2011 0.96 7 0.91 0.93 0.82 0.93 9 0.90 0.92 0.82 0.94 3 0.89 0.91 0.82 0.86 5 0.85 0.91 0.79 0.88 2012 0.96 7 0.88 0.93 0.82 0.92 9 0.88 0.91 0.83 0.94
Attachment A Cronbach alpha formula and reliabilities – NAPLAN 2008 – 2012 Date: 28 June 2013 Formula The formula for computing the NAPLAN reliability is the Cronbach’s Coefficient Alpha. Cronbach alpha reliabilities – NAPLAN 2008 – 2012 In relation to NAPLAN 2008 - 2012, the table below provides the Cronbach alpha reliabilities of each test. Note that the alpha coefficient for Writing is computed using pooled data from all grades. Calendar Year Year Level Reading Writing Spelling Grammar and Punctuation Numeracy 2008 3 0.89 0.94 0.92 0.78 0.87 5 0.89 0.91 0.80 0.88 7 0.88 0.90 0.77 0.93 9 0.88 0.91 0.78 0.92 2009 3 0.88 0.93 0.92 0.87 0.84 5 0.87 0.92 0.84 0.87 7 0.89 0.91 0.83 0.93 9 0.88 0.90 0.79 0.92 2010 3 0.86 0.94 0.93 0.83 0.86 5 0.85 0.92 0.75 0.87 7 0.90 0.93 0.71 0.93 9 0.89 0.90 0.79 0.91 2011 3 0.87 0.96 0.93 0.82 0.87 5 0.87 0.92 0.82 0.87 7 0.91 0.93 0.82 0.93 9 0.90 0.92 0.82 0.94 2012 3 0.89 0.96 0.91 0.82 0.86 5 0.85 0.91 0.79 0.88 7 0.88 0.93 0.82 0.92 9 0.88 0.91 0.83 0.94