tunggal knowledge table student prior calculation TABLES way description score group data strategie criteria perguruan procedure OF tanjung specification design factorial 2008 LIST test having 2012 distribution page discrimination achievement SMP homogeneitie scheffe taught index result interaction DRTA morawa ANOVA homogeneity vii normality treatment two teaching difficulty using comprehension 2x2 frequency dwi summary yayasan reading low strategy reciprocal barlett high