Missing data occurs whenever a valid observation is not available for any one of the experimental unit Loss information Nonapplicability of standard analysis of variance 4/25/ Erlina Ambarwati
Common causes of missing data Improper treatment (nonapplication, incorrect dose, wrong timing) Destruction of experimental plant (physical damage, pest damage, poor germination) Lost of harvested samples Illogical data (recognized after recorded and transcribed) 4/25/ Erlina Ambarwati
The new data do not increasing the experiment error. Experiment error = ( ij ) 2 missing data ij =0 4/25/ Erlina Ambarwati
Missing data in RCBD 0 If missing data = a 4/25/ Erlina Ambarwati
4/25/ Erlina Ambarwati
Anova df total = (t.r-1)-m df error = [(t-1)(r-1)]-m m = numbers of missing data 4/25/ Erlina Ambarwati
Example 1 IIIIIIIV Y i. A B4950a46145+a C D a753+a 16a-8a+a=423 a=47 or 4/25/ Erlina Ambarwati
SVdfBlock3 Treatment3186,67 Error(9-1)-1 Total(15-1)-1 4/25/ Erlina Ambarwati
Example 2 IIIIIIIV Y i. A B4950a46145+a C49b b D b149+a705+a+b i) 16a=4( a)-(705+a+b) 9a+b=471 ii) 16b=4( b)-(705+a+b) a+9b=479 4/25/ Erlina Ambarwati
Elimination/substitution 9a+b=471 9a+81b= b=-3840 b=48 9a+b=471 9a+48=471 a=47 4/25/ Erlina Ambarwati
Konsekuensi adanya missing data untuk uji lanjut dg LSD 4/25/2015Erlina Ambarwati 12 a. Jika tidak ada missing data b. Mengandung satu missing data c. Mengandung dua missing data r 1 dan r 2 : angka ulangan efektif
Cara mencari ulangan efektif r 1 dan r 2 Perhatikan treatment tersebut pada tiap blok dalam hubungannya dengan treatment yang lain yang sama-sama mengalami missing data: Bila treatment I tidak ada nilainya 0 Bila treatment I ada, treatment II tidak ada nilainya ½ Bila treatment I dan treatment II sama-sama adanya nilainya 1 4/25/2015Erlina Ambarwati 13
Contoh 4/25/2015Erlina Ambarwati A B Ө C D Ө BD / ½ r 1 = 3 ½ r 2 = 3 ½