* Two-Way Random Effects Treatment Structure for Estimating Heritability;

data genetics;

 label loc='four randomly selected locations'

       fam='five randomly selected wheat families'

       y='yields';



 loc    block    fam     y

---------------------------

  1       1       1     268

  1       2       1     279

  1       3       1     261

  1       1       2     242

  1       2       2     261

  1       3       2     258

  1       1       3     242

  1       2       3     245

  1       3       3     234

  1       1       4     225

  1       2       4     231

  1       3       4     219

  1       1       5     236

  1       2       5     260

  1       3       5     248

  2       1       1     238

  2       2       1     220

  2       3       1     243

  2       1       2     215

  2       2       2     192

  2       3       2     226

  2       1       3     198

  2       2       3     151

  2       3       3     191

  2       1       4     195

  2       2       4     182

  2       3       4     202

  2       1       5     201

  2       2       5     161

  2       3       5     196

  3       1       1     221

  3       2       1     216

  3       3       1     224

  3       1       2     208

  3       2       2     197

  3       3       2     201

  3       1       3     186

  3       2       3     173

  3       3       3     161

  3       1       4     207

  3       2       4     183

  3       3       4     186

  3       1       5     200

  3       2       5     207

  3       3       5     190

  4       1       1     194

  4       2       1     194

  4       3       1     197

  4       1       2     203

  4       2       2     191

  4       3       2     204

  4       1       3     177

  4       2       3     170

  4       3       3     180

  4       1       4     180

  4       2       4     195

  4       3       4     193

  4       1       5     199

  4       2       5     183

  4       3       5     208