Evaluating a paper (Part I):
Matching claims and evidences.
Interpreting figures.
To skim or not to skim?
To skim
• Article is interesting, but
details not important to you.
• You only need a specific
piece of information from
the article.
• You want to know the
authors’ conclusions, but
don’t care how reliable they
are.
Not to skim
• Your research project is
– directly based on the
conclusion of the article.
– uses data generated by the
previous study.
• The paper claims to present
data that change a longheld assumption.
• The results of the study are
important to society.
Figures
Figures can be:
A concise way of presenting data.
A helpful tool for understanding conclusions.
Figures
Figures can be:
A concise way of presenting data.
A helpful tool for understanding conclusions.
But they can also be:
Intentionally misleading.
Misinterpreted by the author.
Poorly designed / confusing.
Class discussion of Wolfe-Simon paper
Unpacking a figure
PO4
AsO4
Wolfe-Simon F, et al. (2011) Science 332: 1163–1166.
PO4
AsO4
Wolfe-Simon F, et al. (2011) Science 332: 1163–1166.
(B) XRF maps indicated the
correlation between As, iron
(Fe) and zinc (Zn) and not with P
with some variability but
consistent with the trend that
these elements are often found
together (fig. S3, element
correlation plots). The scale bar
in the Zn quadrant of the maps
is as designated and applies to
all parts of the figure. Given the
spatial resolution of these
images, the structures identified
as containing high As, Fe, and Zn
are aggregates of cells. Ranges
as indicated in the color bar run
from cold to hot, in units of μg
cm−2, as follows: As, 0 to 1.6; P,
0 to 40; Fe, 0 to 32.1; and Zn, 0
to 2.8. Standards were used to
calibrate signal and background
(11).
Wolfe-Simon F, et al. (2011) Science 332: 1163–1166.
Overly
complicated
Turnbaugh PJ, et al. (2006). Nature 444:
1027–1031.
Overly
complicated
Turnbaugh PJ, et al. (2009) Sci Transl Med 1: 6ra14.
Discrete data
shown as
continuous
Turnbaugh PJ, et al. (2009) Nature 457: 480–484.
Misleading line of
best fit
Fraser HB, et al. (2002) Science 296 (5568): 750-752
Questions?
Homework
1. Complete “Unpacking a Figure” for any two
(2) figures from your group’s primary
research articles from week 3. (Individual
assignment.)
2. Read the article “Twenty tips for interpreting
scientific claims.” (Sutherland WJ, et al.
(2013) Nature 503: 335-337.