I would do a multilevel model with children nested within teachers.The only question left is how to handle the pre-post testing. It could be a rpeated factor or a growth curve with random intercept and fixed slope. This would not make nay difference unless there was substantial difference in the time between pre and post across classes. If so, the growth model would be preferred. Or you could use the pretest as a covariate. You have plenty of teachers to estimate the random effects of the teachers. Grade could be used as a fixed effect at the teacher level if desired. HLM, MLWin, SAS, and now, I think, SPSS (V12) should handle it. There are other programs but these are the main ones.
Paul R. Swank, Ph.D. Professor, Developmental Pediatrics Medical School UT Health Science Center at Houston -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Harris, Betty A. Sent: Friday, May 21, 2004 11:36 AM To: [EMAIL PROTECTED] Subject: [edstat] Unit of Analysis Paul S Asked: How many teachers in each group? Grade Group K 1st 2nd 3rd All Grades # Classes Treatment 26 31 21 12 90 Comparison 19 23 14 15 71 Total 45 54 35 27 161 # Students tested at both fall and spring Treatment 308 407 344 189 1,248 Comparison 213 237 171 182 803 Total 521 644 515 371 2,051 Criterion referenced tests administered to K and 1st graders Norm referenced achievement tests administered to 2nd and 3rd graders Betty -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Harris, Betty A. Sent: Friday, May 21, 2004 8:08 AM To: [EMAIL PROTECTED] Subject: [edstat] Unit of Analysis Hi all, We have data from a quasiexperimental nonequivalent control group design. A treatment group where the teachers are trained and are implementing a professional development model that involves group and individual coaching to use data to identify their students' component reading skills and target their teaching interventions to get the missing skills in place. They use whole group, small group and individual instruction. A comparison group of classrooms from demographically similar schools doing whatever they normally do. The students were tested in fall and again near the end of the school year. What is the appropriate unit of analysis? And why? What if in some of the treatment group students were grouped into skill-based groups across classrooms for reading instruction? Thanks, Betty . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . ================================================================= . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
