ST 524 Homework 6 NCSU - Fall 2007 1. Variety Trial. Data from a number of yield trials on spring barley conducted at the principal research station of the Oregon Agricultural Experiment Station during the 1983-1984 growing season. Each trial consisted of 12 entries replicated two times in a randomized block design. The three trials have two checks in common: “Benton” and “Steptoe”. The remaining 10 entries in each trial were new selections, and these differed from trial to trial. Compute analysis of variance for the checks Calculate check means Calculate adjustment factor for each trial Calculate adjusted mean yield for new selections in each trial. Get the analysis of variance for the new selections for each trial, Get a combined analysis, and pooled error means square. Get the standard error for check least squares mean, and new selections least squares mean. Get the standard error for the difference between a new selection and a check. Linear Model Yijk i k i j ijk where, i = 1, 2, 3 trials, j = 1, 2, . . ., 30 selections + 2 checks, k = 1, 2 blocks within each trial Results from example in book (Petersen, 1994) Table 6.39 Variety Trial 2 3317.0 3249.5 1.5 1 3395.5 3437.5 134.75 Benton Steptoe Adjustment 3 3324.5 2966.5 -136.75 Mean 3345.67 3217.83 3395.5 3317.0 3324.5 3345.67 3 3437.5 3249.5 2966.5 y StepToe 3217.83 3 Table 6.40 y Benton Source Total Blocks Check Error df 11 5 1 5 SS 2039994.2 883623.7 49024.0 1107436.5 MS 176724.7 49024.0 221469.3 1. Complete information left blank in table 6.41 Table 6.41 Trial Selection 1 2 3 4 5 6 7 8 9 10 Adj. factor aj Benton+LSI Steptoe+LSI 1 2 y y y 3133.0 3200.0 3087.5 4025.0 3678.5 3474.5 3579.0 3599.5 2804.0 2737.0 134.75 Thursday November 1, 2007 2998.2 3065.25 2953.8 3890.2* 3543.8 3339.8 3444.2 3464.8 2669.2 2602.25 3 y 3350.0 3348.5 3516.0 3514.5 2845.5 2844.0 4087.0 4085.5++ 3095.5 3094.0 2833.0 2831.5 2574.5 2673.0 2937.0 2935.5 2733.0 3731.5 3362.0 3360.5 1.50 663.72+ 3345.667 = 4009.387 (4009.867) 663.72+ 3217.833 = 3881.553 (3882.033) y y 3395.5 3178.0 2633.0 3208.0 3666.5 2562.0 2642.5 3241.5 3783.0 2691.5 -136.25 3531.8 3314.25 2769.2 3344.2 3802.8 2698.2 2598.8 3377.8 3919.2* 2827.75 1 ST 524 Homework 6 NCSU - Fall 2007 Table 6.42 Sums of Squares Trial Source Total Block Selection Error df 19 1 9 9 1 709153.2 1472073.8 3005593.2 2613486.2 2 4326438.5 19406.4 3643529.0 708393.1 3 5256706.9 342434.4 3983850.4 930422.1 Pooled Variance Ep SSEc SSESel ,1 SSESel ,2 SSESel ,3 Error df c Error df Sel ,1 Error df Sel ,2 Error df Sel ,3 SSEc SSESel ,1 SSESel ,2 SSESel ,3 p r 1 c 1 p s 1 r 1 p = 3 trials, Ep s = 30 selections , c = 2 checks, r = 2 blocks within each trial 1107346.5 2613486.2 708393.05 930422.05 3 2 1 2 1 3 10 1 2 1 5359648 167489 32 Means and Standard Errors Compare with MSError in combined ANOVA Mean Benton StepToe Difference two check means Standard Error 3345.667 167489 3 2 167.08 3217.833 167489 3 2 167.08 127.834 2 167489 3 2 236.28 p = number of trials; r = number of blocks per trial; c = number of check varieties s = number of new selections per trial. 2. Get the standard error for the difference between two new selections . Adjusted Means and Standard Errors Mean Standard Error Standard Error Adjusted jth Selection in ith trial E p c 1 r c 167489 2 1 2 2 354.42 Difference two adjusted means in same trial ith Difference two adjusted means in different trials Difference jth adjusted mean in trial ith and a check mean 2 Ep r 2 167489 2 409.25 2E p c 1 r c 2 167489 2 1 2 2 501.23 E p pc p c 167489 3 2 3 2 3 2 2 391.83 Thursday November 1, 2007 p r c 2 ST 524 Homework 6 NCSU - Fall 2007 Least Significant Increase: LSI t1 , pr 1 c 1 p r 1 s 1 E p pc p c p r c , LSI t10.05,32 df 167489 3 2 3 2 3 2 2 1.6939 391.8311 663.72 Used to determine which, if any, of the new selections outyield a given check. 3. Rank the new selections. Modify the previous report indicate analyses done with proc mixed and ranking of selections. Report of the statistical analysis (Petersen, 1994) A group of yield trials on new spring barley selections was conducted on the principal research farm of the Oregon Agricultural Experiment Station near Corvallis. A combined Analysis was conducted on a subset of data from three of these trials. There were two checks in common in each trial. These were SteptToe, a long-term baseline variety, and Benton, a recent release. Each trial contained 10 new selections, which differed from trial to trial. The entries in each trial were replicated twice in a randomized block design. The combined analysis produced adjustment factors that could be used to adjust the mean yields of the new selections for yield differences from one trial to another. The mean yield of the baseline, long-term check, Steptoe, was 3217.833 , while that of the recent release, Benton, was 3345.667, For these trials the 5% LSI (least significant increase) for comparing an adjusted selection mean with a check mean was 663.72, Hence any adjusted selection mean greater than3881.553 significantly outyields StepToe, while any adjusted selection mean greater than 4009.387 significantly outyields Benton. Selections that outyield Benton are line 4 in trial 2, while selections 4 in trial1, selection 4 in trial 2 and selection 9 in trial 3 significantly outyield StepToe. 4. Combined Anova: Checks and Selections all three trials The GLM Procedure Class Level Information Class Levels trial block selection 3 2 32 entry idcheck 12 2 Values 1 2 3 1 2 10_1 10_2 10_3 1_1 1_2 1_3 2_1 2_2 2_3 3_1 3_2 3_3 4_1 4_2 4_3 5_1 5_2 5_3 6_1 6_2 6_3 7_1 7_2 7_3 8_1 8_2 8_3 9_1 9_2 9_3 Benton Steptoe 1 10 2 3 4 5 6 7 8 9 Benton Steptoe 0 1 Number of Observations Read Number of Observations Used 72 72 Dependent Variable: yield Source DF Sum of Squares Mean Square F Value Pr > F Model 39 14065384.16 360650.88 2.15 0.0141 Error 32 5359647.72 167488.99 Corrected Total 71 19425031.88 R-Square Coeff Var Root MSE yield Mean 0.724086 12.67123 409.2542 3229.792 Thursday November 1, 2007 3 ST 524 Homework 6 NCSU - Fall 2007 Source DF Type I SS Mean Square F Value Pr > F idcheck(trial) block*idcheck(trial) selection(idcheck) 5 6 28 821744.43 2570642.95 10672996.78 164348.89 428440.49 381178.46 0.98 2.56 2.28 0.4443 0.0388 0.0130 Source DF Type III SS Mean Square F Value Pr > F idcheck(trial) block*idcheck(trial) selection(idcheck) 2 6 28 146895.50 2570642.95 10672996.78 73447.75 428440.49 381178.46 0.44 2.56 2.28 0.6488 0.0388 0.0130 Error SS = 1107346.417 + 2613486.200 + 708393.050+ 930422.050 > 5359648 > Error.ss/32 > 167489 Selection (idcheck) SS = 49024.0833 + 3005593.200 + 3634529.050 + 3983850.450 > 10672997 Alternative Analysis PROC MIXED – ADJUSTED Selection Means Analysis: 3 trials * (2 Blocks each trial * 10 Selections each trial) + 3 trials * 2 Blocks each trial * 2 Checks Total of 30 Selections + 2 Checks = 32 ENTRIES Source Trial Block(trial) Selection Error - Entry*block 31 - Check*Trial 2 - Check vs Selection(trial) = 3 - 1 = 2 Total d.f. 2 3 31 35 = (32-1)*(2-1) + 2 = 31 + (2-1)*(3-1) = 2 + 1*3 – 1 = 2 72-1 = 71 PROC MIXED Get Adjusted Means for Selections within each trial - LSMEANS proc mixed data=barleychk method=reml; class trial block selection idcheck entry; model yield= trial selection /ddfm=kr; random block (trial); lsmeans trial selection ; The Mixed Procedure Model Information Data Set Dependent Variable Covariance Structure Estimation Method Residual Variance Method Fixed Effects SE Method Degrees of Freedom Method WORK.BARLEYCHK yield Variance Components REML Profile Prasad-Rao-JeskeKackar-Harville Kenward-Roger Class Level Information Class trial block selection Thursday November 1, 2007 Levels 3 2 32 Values 1 2 3 1 2 10_1 10_2 10_3 1_1 1_2 1_3 2_1 4 ST 524 Homework 6 idcheck entry NCSU - Fall 2007 2_2 2_3 3_1 3_2 3_3 4_1 4_2 4_3 5_1 5_2 5_3 6_1 6_2 6_3 7_1 7_2 7_3 8_1 8_2 8_3 9_1 9_2 9_3 Benton Steptoe 0 1 1 10 2 3 4 5 6 7 8 9 Benton 2 12 Steptoe Dimensions Covariance Parameters Columns in X Columns in Z Subjects Max Obs Per Subject 2 36 6 1 72 Number of Observations Number of Observations Read Number of Observations Used Number of Observations Not Used 72 72 0 Iteration History Iteration Evaluations 0 1 -2 Res Log Like Criterion 1 599.33857463 1 593.71674291 Convergence criteria met. 0.00000000 Covariance Parameter Estimates Cov Parm Estimate block(trial) Residual 52997 158484 Fit Statistics -2 Res Log Likelihood AIC (smaller is better) AICC (smaller is better) BIC (smaller is better) 593.7 597.7 598.1 597.3 Type 3 Tests of Fixed Effects Effect trial selection Effect trial trial trial selection selection selection selection selection selection trial 1 2 3 10_1 10_2 10_3 1_1 1_2 Thursday November 1, 2007 Num DF Den DF F Value Pr > F 2 31 11 35 0.28 2.18 0.7627 0.0134 Least Squares Means Standard Estimate Error 3358.05 3224.80 3087.05 2602.25 3360.50 2827.75 2998.25 3348.50 235.13 235.13 235.13 338.36 338.36 338.36 338.36 338.36 DF t Value Pr > |t| 8.06 8.06 8.06 37.8 37.8 37.8 37.8 37.8 14.28 13.71 13.13 7.69 9.93 8.36 8.86 9.90 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 5 ST 524 selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection selection Homework 6 1_3 2_1 2_2 2_3 3_1 3_2 3_3 4_1 4_2 4_3 5_1 5_2 5_3 6_1 6_2 6_3 7_1 7_2 7_3 8_1 8_2 8_3 9_1 9_2 9_3 Benton Steptoe 3531.75 3065.25 3514.50 3323.25 2952.75 2844.00 2769.25 3890.25 4085.50 3344.25 3543.75 3094.00 3802.75 3339.75 2831.50 2698.25 3444.25 2673.00 2598.75 3464.75 2935.50 3377.75 2669.25 3731.50 3919.25 3345.67 3217.83 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 338.36 187.74 187.74 NCSU - Fall 2007 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 37.8 21.7 21.7 10.44 9.06 10.39 9.82 8.73 8.41 8.18 11.50 12.07 9.88 10.47 9.14 11.24 9.87 8.37 7.97 10.18 7.90 7.68 10.24 8.68 9.98 7.89 11.03 11.58 17.82 17.14 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 Estimates of LSMEANS for L1T1 broad and narrow sense Estimates Label Selection 1 trial 1 L1 T1 AdjMN s.e.(LSMEAN L1 T1 narrow) s.e.(LSMEAN L1 T1) = = Estimate 3133.00 281.50 2998.25 338.36 Standard Error 35 37.8 DF 11.13 8.86 t Value Pr > |t| <.0001 <.0001 158484 281.4996 2 52997 52997+158484 338.49 6 2 Estimates of LSMEANS for L1T1, L2T1, L2T3 Benton and pairwise differences. Estimates Label L2 T1 AdjMN L2 T3 AdjMN L1-L2 , T1 AdjMNDiff L1_T1-L2_T3 AdjMNDIFF Benton LSMEAN AdjMN L1 T1 - Benton Estimate 3065.25 3323.25 -67.00 -325.00 3345.67 -347.42 Standard Error 338.36 338.36 398.10 487.57 187.74 363.41 DF 37.8 37.8 35 35 21.7 35 t Value 9.06 9.82 -0.17 -0.67 17.82 -0.96 Pr > |t| <.0001 <.0001 0.8673 0.5094 <.0001 0.3456 Standard Error for Selection means and pairwise mean differences s.e.(Difference between two adjusted means within the same trial) = 2 158484 398.10 2 s.e.(Difference between two adjusted means in different trials) = Thursday November 1, 2007 6 ST 524 2 Homework 6 NCSU - Fall 2007 158484 2+1 487.57 2 2 s.e.(Benton Check mean) = 52997 158484 187.74 6 6 s.e.(Difference between an adjusted means and a check mean) = 3 52997 4 158484 363.53 6 6 Considering PROC MIXED results Standard Errors Mean Standard Error (CLASSICAL) Difference two adjusted means in same trial ith Difference two adjusted means in different trials Difference jth adjusted mean in trial ith and a check mean 2 167489 2 409.25 2 167489 2 1 2 2 501.23 167489 3 2 3 2 3 2 2 391.83 Standard Error (PROC MIXED) 2 158484 398.10 2 2 158484 2+1 487.57 2 2 363.41 (from Estimate or LSMEAN Differences) Least Significant Increase: LSI t1 , pr 1 c 1 p r 1 s 1 E p pc p c p r c , LSI t10.05,35 df 363.41 1.6896 363.41 614.02 Used to determine which, if any, of the new selections outyield a given check Report of the statistical analysis (Petersen, 1994) A group of yield trials on new spring barley selections was conducted on the principal research farm of the Oregon Agricultural Experiment Station near Corvallis. A combined Analysis was conducted on a subset of data from three of these trials. There were two checks in common in each trial. These were SteptToe, a long-term baseline variety, and Benton, a recent release. Each trial contained 10 new selections, which differed from trial to trial. The entries in each trial were replicated twice in a randomized block design. The combined analysis produced adjustment factors that could be used to adjust the mean yields of the new selections for yield differences from one trial to another. The variation among blocks within reps is 52997, while the residual variance is 52997. The mean yield of the baseline, long-term check, Steptoe, was 3217.833 , while that of the recent release, Benton, was 3345.667, For these trials the 5% LSI (least significant increase) for comparing an adjusted selection mean with a check mean was 614.02, Hence any adjusted selection mean greater than3831.85 significantly outyields StepToe, while any adjusted selection mean greater than 3959.69 significantly outyields Benton. Thursday November 1, 2007 7 ST 524 Homework 6 NCSU - Fall 2007 Selections that outyield Benton are line 4 in trial 2, while selections 4 in trial1, selection 4 in trial 2 and selection 9 in trial 3 significantly outyield StepToe. Trial Selection 1 2 3 4 5 6 7 8 9 10 Adj. factor aj Benton+LSI Steptoe+LSI Thursday November 1, 2007 1 2 2 3 y y y 2998.2 3065.25 2953.8 3890.2* 3543.8 3339.8 3444.2 3464.8 2669.2 2602.25 3348.5 3514.5 2844.0 4085.5++ 3094.0 2831.5 2673.0 2935.5 3731.5 3360.5 3531.8 3314.25 2769.2 3344.2 3802.8 2698.2 2598.8 3377.8 3919.2* 2827.75 614.02 + 3345.67 =3959.69 614.02 + 3217.83 = 3831.85 8 ST 524 Homework 6 NCSU - Fall 2007 Question 2. Alpha Design Design Layout Thursday November 1, 2007 „-----------------------…-----------------------† | | block | | ‡---…---…---…---…---…---‰ | | 1 | 2 | 3 | 4 | 5 | 6 | ‡-----------…-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ |replication|plot | | | | | | | ‡-----------ˆ-----------‰ | | | | | | |1 |1 | 11| 21| 23| 13| 17| 6| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |2 | 4| 10| 14| 3| 15| 12| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |3 | 5| 20| 16| 19| 7| 24| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |4 | 22| 2| 18| 8| 1| 9| ‡-----------ˆ-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ |2 |1 | 8| 24| 12| 5| 2| 19| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |2 | 20| 15| 11| 9| 18| 7| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |3 | 14| 3| 21| 10| 13| 6| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |4 | 4| 23| 17| 1| 22| 16| ‡-----------ˆ-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ |3 |1 | 11| 2| 17| 12| 21| 3| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |2 | 1| 15| 18| 13| 22| 5| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |3 | 14| 9| 4| 10| 16| 20| | ‡-----------ˆ---ˆ---ˆ---ˆ---ˆ---ˆ---‰ | |4 | 19| 8| 6| 23| 24| 7| Š-----------‹-----------‹---‹---‹---‹---‹---‹---Œ 9 ST 524 Homework 6 NCSU - Fall 2007 Data „-----------------------…-----------------------------------------------† block ‡-------…-------…-------…-------…-------…-------‰ 1 2 3 4 5 6 ‡-----------…-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -replication-plot ‡-----------ˆ-----------‰ -1 -1 - 4.1172- 4.6540- 4.2323- 4.2530- 4.7876- 4.7085‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -2 - 4.4461- 4.1736- 4.7572- 3.3420- 5.0902- 5.2560‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -3 - 5.8757- 4.0141- 4.4906- 4.7269- 4.1505- 4.9577‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -4 - 4.5784- 4.3350- 3.9737- 4.9989- 5.1202- 3.3986‡-----------ˆ-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -2 -1 - 3.9926- 3.9039- 5.3127- 5.1202- 5.1566- 5.3148‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -2 - 3.6056- 4.9114- 5.1163- 4.2955- 5.0988- 4.6297‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -3 - 4.5294- 3.7999- 5.3802- 4.9057- 5.4840- 5.1751‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -4 - 4.3599- 4.3042- 5.0744- 5.7161- 5.0969- 5.3024‡-----------ˆ-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -3 -1 - 3.9205- 4.0510- 4.3234- 4.1746- 4.4130- 2.8873‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -2 - 4.6512- 4.6783- 4.2486- 4.7512- 4.2397- 4.1972‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -3 - 4.3887- 3.1407- 4.3960- 4.0875- 4.3852- 3.7349‡-----------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------ˆ-------‰ -4 - 4.5552- 3.9821- 4.2474- 3.8721- 3.5655- 3.6096Š-----------‹-----------‹-------‹-------‹-------‹-------‹-------‹-------Œ Model 3 Replicates , 6 blocks of size 4 each, 24 entries, 3 repetitions per entry Linear Model Yijh j bh j i eijh k=4 plots per block, r=3 replications, t=24 entries, blocks=6 per replication entries by block table: trial 1 | trial 2 | trial 3 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 2 3 4 5 * 6 1 2 3 4 * 5 6 1 * * * * 2 3 4 5 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 6 * * * * Entry 1 in blocks 1_5, 2_4 and 3_1 Block 1 in trial 1 : Entries 1 , 7, 15, 17 Some entries are in the same block once, 1 Thursday November 1, 2007 10 ST 524 Homework 6 NCSU - Fall 2007 Some entries do not occur together in any of the blocks, 0 1 for Entry 1 vs entries : 7, 15, 17 , 5, 9, 10 , 12, 14, 19 Q2.1 Calculate the following PROC GLM Eb Ee k r 1 Eb 0.240240 0.083463 0.081573 A 4 3 1 0.240240 A Adjustment factor Adjustment factor Effective error mean square Ee,lattice e2 1 rkA k 1 Ee,lattice 0.083463 1 3 4 0.081573 4 1 0.099803 pooled error Erb SSB SSE t 1 r 1 pooled error Erb 3.603599 2.587355 0.134586 24 1 3 1 Same as Error MS when ignoring blocks within reps , Taken as if design is RCB with 3 blocks. Sometimes recommended to use RCBD as an alternative for analysis when Eb Ee , and the efficiency is not that high. % relative precision RP Erb 100 Ee,lattice 0.134586 134.85% 0.099803 *********************************************************; PROC MIXED Q2.2 Questions a) Find the standard error of the differences of two lines. Standard Label Estimate Error DF t Value entry 1 vs 2 entry 1 vs 2 b) 0.3146 0.6292 0.1381 0.2763 38.2 38.2 2.28 2.28 Pr > |t| 0.0285 0.0285 **divisor=2 **divisor=1 Calculate the standard error of the LSMEAN for Line (Entry) 1, narrow and broad sense. Explain the differences. Standard Label Estimate Error DF t Value Pr > |t| entry 1 LSMEAN 5.1077 0.1995 44.1 25.60 <.0001 entry 1 LSMEAN BLUP 5.1625 0.1685 29.7 30.63 <.0001 Narrow space LSMEAN is calculated directly included in Broad Space LSMEAN is calculated in the estimation of conditional in the observed effects of blocks, which are not the estimation of the standard error of the entry mean unconditional in the observed random effects, which are included the standard error of the entry mean Thursday November 1, 2007 11 ST 524 Homework 6 NCSU - Fall 2007 Other calculations Variance for the difference of two treatment means in class 1 , they can be found in the same block. 2 4 0.08523 2k e2 var y i.. y i '.. 0.068184 r k 1 1 3 4 1 1 s.e. y i.. y i '.. av. var y i.. y i '.. 0.068184 0.2611 Variance for the difference of two treatment means in class block. 0, they do not share a common 2 4 0.08523 2k e2 var y i.. y i '.. 0.07576 r k 1 1 3 4 1 0 s.e. y i.. y i '.. av. var y i.. y i '.. 0.07576 0.2752 Compare with table below, 1 for Entry 1 vs entries : 7, 15, 17 , 5, 9, 10 , 12, 14, 19 Differences of Least Squares Means Effect entry _entry Estimate Standard Error DF t Value Pr > |t| entry 1 2 0.6292 0.2763 38.2 2.28 0.0285 entry 1 3 1.6085 0.2749 37.7 5.85 <.0001 entry 1 4 0.6176 0.2749 37.7 2.25 0.0306 entry 1 5 0.07049 0.2619 34.8 0.27 0.7894 entry 1 6 0.5710 0.2749 37.7 2.08 0.0447 entry 1 7 0.9966 0.2619 34.8 3.81 0.0005 entry 1 8 0.5801 0.2750 37.7 2.11 0.0416 entry 1 9 1.6055 0.2631 35.3 6.10 <.0001 entry 1 10 0.7345 0.2643 35.9 2.78 0.0086 entry 1 11 0.8244 0.2621 35 3.15 0.0034 . . . c) Run a pairwise comparison test for the lsmeans and use the macro pdmix80 to represent the differences among the entries. --------------------------- Effect=entry Obs entry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 5 15 19 21 14 13 12 16 17 6 8 22 4 2 10 18 11 23 24 Thursday November 1, 2007 Method=LSD(P<.01) no block in common In block 1 Trial 1 Set=1 ---------------------------- Estimate Standard Error Letter Group 5.1077 5.0372 4.9691 4.8403 4.7950 4.7757 4.7579 4.7553 4.7301 4.6026 4.5367 4.5276 4.5275 4.4901 4.4785 4.3732 4.3617 4.2833 4.2524 4.1539 0.1995 0.1994 0.1994 0.1994 0.1994 0.1994 0.1994 0.1995 0.1995 0.1994 0.1994 0.1995 0.1994 0.1995 0.1995 0.1995 0.1995 0.1995 0.1994 0.1995 A AB ABC ABCD ABCDE ABCDE ABCDEF ABCDEF ABCDEF ABCDEF ABCDEF ABCDEF ABCDEF ABCDEF ABCDEF BCDEF ABCDEF CDEF CDEF DEFG 12 ST 524 Homework 6 21 22 23 24 Entries 1 and 5 9 3 7 20 9 3 4.1111 4.0400 3.5022 3.4992 are significantly different 0.1995 0.1994 0.1994 0.1995 NCSU - Fall 2007 EFG FG G G (higher mean) from entries 11 23 24 7 20 One reason for alpha design approximated values when using above formulas, although there might be better approximations. Look at the standard errors of mean differences. Thursday November 1, 2007 13