The document discusses common misuses of statistics in biology publications. It addresses issues like using unnecessary 3D graphs, graphs that do not show data variations or spreads, incorrectly taking the mean of ordinal data, assuming linear relationships without checking residuals, and engaging in unnecessary multiple testing. The author advocates for showing raw data when possible, avoiding extra multiple testing, using non-parametric and Bayesian alternatives when assumptions are violated, including power calculations, and generally being more careful about how and when to apply statistical analyses.

1. Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Playing dumb:the misuse of Statistics in
Biology
Luiz Max F. de Carvalho
Program for Scientific Computing (PROCC), Fiocruz
Statistics has
confirmed it.
What!?
What should I
do then?
November 26, 2012

2. Outline
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
1 Preliminaries
2 Braindead graphs
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?
3 Statistics has confirmed it. What!?
4 What should I do then?

3. Statistics – seems like but – is not magic!
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?
In its origins, created to make sense of incomplete
data/information;
A useful, powerful and flexible way of coping with
uncertainty;
Widespread (mis)use in modern science

4. Braindead graphs I - Why the heck 3D?
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?

5. Braindead graphs II - stick with 2D
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?

6. Spreads matter
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?

7. Dynamite is a bomb!
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?
Don’t show data variation;
Who said means mean anything?
Where are the data?

8. Dynamite is a bomb!
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?

9. I took the mean of an intervalar scale! Oh, please...
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?
Beverage
Coca-Cola
Pepsi
Dr. Pepper
7up
Ginger ale
Average Rank
1.6
3.3
4.4
4.9
5.2

10. Oh, so tiny!
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?

11. Oh, so tiny?
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?
Asymptotic normality;
Power;
Multiple testing

12. There’s a linear relationship. What!?
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?

13. There’s a linear relationship. What!?
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?
OLS assumes normality and homokedasticity
You only need two points to make a straight line
Residuals analysis is as much important as everything else

14. What should I do then?
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Try and show the data;
Avoid unecessary multiple testing
Preliminaries
Non-parametrics and Bayesian alternatives
Braindead
graphs
Power Calculations
Statistics has
confirmed it.
What!?
What should I
do then?

15. Tanqui´ i´ v´ri m˜ti!
u u e
a
Playing
dumb:the
misuse of
Statistics in
Biology
Luiz Max F.
de Carvalho
Program for
Scientific
Computing
(PROCC),
Fiocruz
Preliminaries
Braindead
graphs
Statistics has
confirmed it.
What!?
What should I
do then?