use http://www.gseis.ucla.edu/courses/data/crf322, clear
tab1 method book computer
-> tabulation of method
method | Freq. Percent Cum.
------------+-----------------------------------
1 | 24 33.33 33.33
2 | 24 33.33 66.67
3 | 24 33.33 100.00
------------+-----------------------------------
Total | 72 100.00
-> tabulation of book
book | Freq. Percent Cum.
------------+-----------------------------------
1 | 36 50.00 50.00
2 | 36 50.00 100.00
------------+-----------------------------------
Total | 72 100.00
-> tabulation of computer
computer | Freq. Percent Cum.
------------+-----------------------------------
0 | 36 50.00 50.00
1 | 36 50.00 100.00
------------+-----------------------------------
Total | 72 100.00
summarize test, detail
test
-------------------------------------------------------------
Percentiles Smallest
1% 152 152
5% 158 156
10% 161 157 Obs 72
25% 170.5 158 Sum of Wgt. 72
50% 182.5 Mean 184.5
Largest Std. Dev. 17.83887
75% 198.5 217
90% 206 219 Variance 318.2254
95% 217 224 Skewness .2806147
99% 228 228 Kurtosis 2.387098
stem test
Stem-and-leaf plot for test
15* | 2
15. | 6789
16* | 0012444
16. | 569
17* | 000133334
17. | 556699
18* | 00001234
18. | 6779
19* | 00004444
19. | 56789999
20* | 12344
20. | 5669
21* |
21. | 579
22* | 4
22. | 8
kdensity test, normal
table book computer, by(method) con(freq)
----------------------
method | computer
and book | 0 1
----------+-----------
1 |
1 | 6 6
2 | 6 6
----------+-----------
2 |
1 | 6 6
2 | 6 6
----------+-----------
3 |
1 | 6 6
2 | 6 6
----------------------
table book computer, by(method) con(mean test)
----------------------
method | computer
and book | 0 1
----------+-----------
1 |
1 | 169 168
2 | 173 188
----------+-----------
2 |
1 | 172 204
2 | 187 200
----------+-----------
3 |
1 | 173 189
2 | 182 209
----------------------
table book computer, by(method) con(sd test)
------------------------------
method | computer
and book | 0 1
----------+-------------------
1 |
1 | 14.81891 8.602325
2 | 9.797959 10.86278
----------+-------------------
2 |
1 | 10.93618 12.68069
2 | 14.01428 10.07968
----------+-------------------
3 |
1 | 11.6619 12.61745
2 | 17.1114 14.3527
------------------------------
egen grp=group(method book computer)
graph box test, over(method) over(book) over(computer)
histogram test, by(method book computer)
anova test method book computer meth*book meth*com book*com meth*book*com
Number of obs = 72 R-squared = 0.5840
Root MSE = 12.5167 Adj R-squared = 0.5077
Source | Partial SS df MS F Prob > F
---------------------+----------------------------------------------------
Model | 13194.00 11 1199.45455 7.66 0.0000
|
method | 3675.00 2 1837.50 11.73 0.0000
book | 2048.00 1 2048.00 13.07 0.0006
computer | 5202.00 1 5202.00 33.20 0.0000
method*book | 259.00 2 129.50 0.83 0.4425
method*computer | 903.00 2 451.50 2.88 0.0638
book*computer | 32.00 1 32.00 0.20 0.6529
method*book*computer | 1075.00 2 537.50 3.43 0.0388
|
Residual | 9400.00 60 156.666667
---------------------+----------------------------------------------------
Total | 22594.00 71 318.225352
predict cmean
local ssr=e(rss)
local dfr=e(df_r)
omega2 meth*book*com
omega squared for meth*book*com = 0.0633
effect size = 0.2599
omega2 method
omega squared for method = 0.2296
effect size = 0.5459
omega2 book
omega squared for book = 0.1436
effect size = 0.4095
omega2 computer
omega squared for computer = 0.3090
effect size = 0.6688
twoway (line cmean computer if book==1 & method==1)(line cmean computer if book==2 & method==1)
twoway (line cmean computer if book==1 & method==2)(line cmean computer if book==2 & method==2)
twoway (line cmean computer if book==1 & method==3)(line cmean computer if book==2 & method==3)
anova test book computer book*computer if method==1
Number of obs = 24 R-squared = 0.3779
Root MSE = 11.265 Adj R-squared = 0.2846
Source | Partial SS df MS F Prob > F
--------------+----------------------------------------------------
Model | 1542.00 3 514.00 4.05 0.0211
|
book | 864.00 1 864.00 6.81 0.0168
computer | 294.00 1 294.00 2.32 0.1436
book*computer | 384.00 1 384.00 3.03 0.0973
|
Residual | 2538.00 20 126.90
--------------+----------------------------------------------------
Total | 4080.00 23 177.391304
test5 book*computer, sse(`ssr') dfe(`dfr')
/* net from http://www.ats.ucla.edu/stat/stata/ado/ */
/* net install test5 */
Source Partial SS df MS F Prob > F
book*computer 384.00 1 384.00 2.45 0.1227
Residual 9400.00 60 156.67
anova test book computer book*computer if method==2
Number of obs = 24 R-squared = 0.5653
Root MSE = 12.025 Adj R-squared = 0.5001
Source | Partial SS df MS F Prob > F
--------------+----------------------------------------------------
Model | 3760.50 3 1253.50 8.67 0.0007
|
book | 181.50 1 181.50 1.26 0.2758
computer | 3037.50 1 3037.50 21.01 0.0002
book*computer | 541.50 1 541.50 3.74 0.0672
|
Residual | 2892.00 20 144.60
--------------+----------------------------------------------------
Total | 6652.50 23 289.23913
test5 book*computer, sse(`ssr') dfe(`dfr')
Source Partial SS df MS F Prob > F
book*computer 541.50 1 541.50 3.46 0.0679
Residual 9400.00 60 156.67
anova test book computer book*computer if method==3
Number of obs = 24 R-squared = 0.5151
Root MSE = 14.089 Adj R-squared = 0.4423
Source | Partial SS df MS F Prob > F
--------------+----------------------------------------------------
Model | 4216.50 3 1405.50 7.08 0.0020
|
book | 1261.50 1 1261.50 6.36 0.0203
computer | 2773.50 1 2773.50 13.97 0.0013
book*computer | 181.50 1 181.50 0.91 0.3504
|
Residual | 3970.00 20 198.50
--------------+----------------------------------------------------
Total | 8186.50 23 355.934783
test5 book*computer, sse(`ssr') dfe(`dfr')
Source Partial SS df MS F Prob > F
book*computer 181.50 1 181.50 1.16 0.2861
Residual 9400.00 60 156.67
cmeans test method book if computer==0, label
twoway (line cmean book if computer==0 & method==1)(line cmean book if computer==0 & method==2)(line cmean book if computer==0 & method==3)
cmeans test method book if computer==1, label
twoway (line cmean book if computer==1 & method==1)(line cmean book if computer==1 & method==2)(line cmean book if computer==1 & method==3)
anova test method book method*book if computer==0
Number of obs = 36 R-squared = 0.2136
Root MSE = 13.2941 Adj R-squared = 0.0825
Source | Partial SS df MS F Prob > F
------------+----------------------------------------------------
Model | 1440.00 5 288.00 1.63 0.1825
|
method | 474.00 2 237.00 1.34 0.2768
book | 784.00 1 784.00 4.44 0.0437
method*book | 182.00 2 91.00 0.51 0.6027
|
Residual | 5302.00 30 176.733333
------------+----------------------------------------------------
Total | 6742.00 35 192.628571
test5 method*book, sse(`ssr') dfe(`dfr')
Source Partial SS df MS F Prob > F
method*book 182.00 2 91.00 0.58 0.5625
Residual 9400.00 60 156.67
anova test method book method*book if computer==1
Number of obs = 36 R-squared = 0.6152
Root MSE = 11.6876 Adj R-squared = 0.5511
Source | Partial SS df MS F Prob > F
------------+----------------------------------------------------
Model | 6552.00 5 1310.40 9.59 0.0000
|
method | 4104.00 2 2052.00 15.02 0.0000
book | 1296.00 1 1296.00 9.49 0.0044
method*book | 1152.00 2 576.00 4.22 0.0243
|
Residual | 4098.00 30 136.60
------------+----------------------------------------------------
Total | 10650.00 35 304.285714
test5 method*book, sse(`ssr') dfe(`dfr')
Source Partial SS df MS F Prob > F
method*book 1152.00 2 576.00 3.68 0.0312
Residual 9400.00 60 156.67
Linear Statistical Models Course
Phil Ender, 10apr06, 27apr01