Raw data sets for the examples

Return to statistical analysis

It should be possible to copy the data either directly into your statistical package or via EXCEL or other spread sheet.

Data set 1. Mice were maintained on diets containing either Roast (Gp 1) or Raw (Gp 2) peanuts. The aim of the experiment was to see whether this influenced body weight. Assume that a mouse is the experimental unit (not real data)

    Gp   Wt
    1      34
    1      46
    1      35
    1      42
    1      42
    1      42
    1      44
    1      43
    1      39
    1      34
    1      46
    2      42
    2      42
    2      51
    2      48
    2      44
    2      43
    2      41
    2      45
    2      42
    2      44
    2      44

Data set 2. Mice were injected i.p. with a vehicle (Control, Carc=1), Methylcholanthrene (Carc=2), or Urethane (Carc=3) and after a suitable time period the number of micronuclei (mn) in the polychromatic erythrocytes was counted from a sample of blood, using a new technique. The aim was to compare the new and old techniques, but only the counts using the new technique are given here

Carc     mn
1          1.48
1          2.23
1          1.87
1          1.88
1          1.90
1          1.59
1          1.23
1          2.06
1          2.15
1          0.66
1          0.33
1          1.22
2          3.04
2          3.48
2          2.49
2          3.56
2          6.10
2          2.81
2          3.85
2          2.90
2          5.39
2          1.57
2          2.15
2          2.34
3          1.26
3          2.13
3          1.87
3          0.75
3          2.00
3        1.98
3        2.27
3        2.34
3        1.55
3        2.26
3        1.76
3          0.83

Data set 3. A randomised block (or crossover) design. Mice were offered two water bottles, on containing a test substance and the mount of fluid consumed from the test bottle was expressed as a percentage of total fluid intake. There were four mouse cages, each containing two mice. Test solutions were given in random order for 5 days, water over the weekend, then another test solution etc. The experimental unit is a cage with two mice for a week. Blocking factor was the cage.

Percent  Cage  Treatment
54.9       1        Water
48.2       2        Water
49.9       3        Water
50.4       4        Water
69.6       1        Saccharin
61.1       2        Saccharin
58.2       3        Saccharin
55.3       4        Saccharin
61.9       1        Salt
43.9       2        Salt
53.4       3        Salt
50.7       4        Salt
78.3       1        Sucrose
81.5       2        Sucrose
74.7       3        Sucrose
73.6       4        Sucrose
69.4       1        Ethanol
60.9       2        Ethanol
68.5       3        Ethanol
64.5       4        Ethanol
 

Data set 4. Mice of two strains (C3H and CD-1) were injected with a vehicle (Control) or Chloramphenicol and the number of red blood cells (RBC) was counted. This is the data given in the page on Factorial Experimental Designs. It is part of a much larger study involving 4 inbred strains and CD-1 with six dose levels. An extra column “Group” has been added so that a stripchart can be used to look at the raw data.

Strain Treatment RBC       Group
C3H    Control   7.85       C3H-C
C3H    Control   8.77       C3H-C
C3H    Control   8.48       C3H-C
C3H    Control   8.22       C3H-C
CD-1   Control   9.01     CD-C
CD-1   Control   7.76     CD-C
CD-1   Control   8.42     CD-C
CD-1   Control   8.83     CD-C
C3H    Chloram   7.81      C3H-T
C3H    Chloram   7.21      C3H-T
C3H    Chloram   6.96      C3H-T
C3H    Chloram   7.10      C3H-T
CD-1 Chloram  9.18     CD-T
CD-1 Chloram  8.31     CD-T
CD-1 Chloram  8.47     CD-T
CD-1 Chloram  8.67     CD-T
 

Data set 5. A split plot experimental design (see section on “Experimental designs” (simulated data)

ID Cage Sex Treatment Weight     
1        1     M     Trt             6.7
2        2     M     Trt             6.8
3        3     M     Trt             5.1
4        4     M     Trt             6.9
5        5     M     Trt             6.8
6        6     M     Trt             5.3
7        7     F     Trt             3.1
8        8     F     Trt             2.3
9        9     F     Trt             2.6
10   10    F      Trt           1.9
11   11    F      Trt           4.4
12   12    F      Trt           3.8
13     1     M     Control   7.5
14     2     M     Control   8.7
15     3     M     Control   7.4
16     4     M     Control   7.2
17     5     M     Control   7.4
18     6     M     Control   7.3
19     7     F     Control     5.1
20     8     F     Control     4.2
21     9     F     Control     3.7
22   10    F    Control    3.2
23   11    F    Control    6.3
24   12    F    Control    4.4

 

Data set 6. Body and organ weight in male mice (unpublished data) for exercises in correlation

body   liver  testis   fat  kidney brain
34.79  1.58   0.22  1.31   0.48  0.47
31.61  1.55   0.24  0.73   0.46  0.46
33.62  1.58   0.19  1.31   0.44  0.45
40.53  1.71   0.20  2.03   0.46  0.45
31.48  1.51   0.20  0.97   0.44  0.46
32.95  1.62   0.19  0.86   0.52  0.47
32.22  1.48   0.21  0.96   0.44  0.46
35.96  1.65   0.19  1.49   0.47  0.45
38.87  1.73   0.24  1.93   0.53  0.48
34.93  1.56   0.24  1.18   0.45  0.47
35.71  1.64   0.19  1.32   0.46  0.44
35.55  1.73   0.21  1.29   0.48  0.47
34.53  1.58   0.19  1.09   0.47  0.47
32.43  1.43   0.19  1.17   0.41  0.44
35.20  1.69   0.19  1.38   0.45  0.46

Data set 7. Lesion diameter (cm) in pig liver following microwave ablation at various levels of power (Watts).

 Strickland AD, Clegg PJ, Cronin NJ et al. Experimental study of large-volume microwave ablation in the liver. Br J Surg 2002;89:1003-1007.

Diam   Power
1.9    36
3.3    50
3.2    50
2.8    50
2.8    50
2.4    50
2.7    50
3.2    50
3.8    50
3.4    50
3.0    50
4.7  100
4.0  100
3.5  100
3.5  100
3.9  100
4.8  100
4.4  100
4.3  100
3.7  100
3.5  100
3.8  100
5.5  150
5.0  150
4.4  150
4.4  150
6.0  150
6.5  150
5.0  150
5.0  150
5.8  200
6.0  200
 

 

Return to statistical analysis