Graphical Data Displays and Interpretation

Reading Comprehension

0 1 2 3 4 5 6GRADE

3

4

5

6

7

8

9

10

11

12

Age

Eq

uiv

ale

nt S

core

English-OnlyBilingual

Program

0 1 2 3 4 5 63

6

9

12

Figure 6

“White space”

English oral proficiency, reading and writing development and redesignation probability from LEP to FEP as a function of grade level. District A.

0 1 2 3 4 5 6 7GRADE

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Me

an

Sco

re, 1

= C

r ite

r io

n

Oral EnglishReadingWritingRedesignation

Measure

Figure 2

John Tukey, Exploratory Data Analysis.

Edward Tufte, The Visual Display of Quantitative Information.

Statistical Program: SYSTAT

Tufte Principles of Graphical Excellence

Graphical excellence is the well-designed presentation of interesting data -- a matter of substance, of statistics, and of design.

Graphical excellence consists of complex ideas communicated with clarity, precision, and efficiency.

Graphical excellence is that which gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space.

Graphical excellence is nearly always multivariate.

Graphical excellence requires telling the truth about the data.

Johnson & Newport (1989) Critical period effects in second-language learning: The influence of maturational state on the acquisition of English as a second language.

Cognitive Psychology, 21, 60-99.

Pre-Puberty

2 4 6 8 10 12 14 16Age of Arrival

210

220

230

240

250

260

270

280

Eng

l ish

Pr o

fi cie

ncy

Post-Puberty

10 20 30 40Age of Arrival

160

170

180

190

200

210

220

230

240

250

260

Eng

li sh

Pro

f icie

ncy

r=-.87 r=-.16

Johnson & Newport, combined across age groups.

All Subjects

0 10 20 30 40Age of Arrival

150

200

250

300E

nglis

h P

rofic

ien c

y

Johnson & Newport, scaled properly.

All Subjects

0 10 20 30 40Age of Arrival

0

100

200

300E

nglis

h P

rofic

ien c

y

r=-.87 r=-.49

Tufte Principles of Graphical Excellence

Graphical excellence is the well-designed presentation of interesting data -- a matter of substance, of statistics, and of design.

Graphical excellence consists of complex ideas communicated with clarity, precision, and efficiency.

Graphical excellence is that which gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space.

Graphical excellence is nearly always multivariate.

Graphical excellence requires telling the truth about the data.