Analysis of variance of plant identification pretest scores by groups Means and standard deviations of written posttest scores by technique Analysis of variance of written posttest scores by groups Means and standard deviations of plant identi fication posttest scores by technique Analysis of variance of plant identification posttest scores by groups Mean gain scores and standard deviations for scores between plant identification pretest and plant identification posttest by technique T-test analysis of gain scores between written and plant identification pretests and written and plant identification posttests by technique Covariates identified by steptd.se regression for written posttest scores Analysis of covariance for written posttest scores when student enrollment in senior high school was f* r-s f ^ ft 4" fx X.