List of figures
Figure 1.Cumulative word counts of the Conversation, Fiction, Instructional, Informative, and Personal correspondence subcorpora of the TEC per
textbook volume85
Figure 2.Correlation matrix of the normalised counts in Table 998
Figure 3.Mean scores of general spoken and written registers of English on Biber’s (1988)
Dimension 1 (as summarised in Biber & Conrad 2019: 292)107
Figure 4.Comparison of the conversation, fiction and informative texts from the TEC with the three corresponding target language reference
corpora on Biber’s (1988) Dimension 1 (as calculated by the MAT) (Le Foll 2021. Zenodo.
)109
Figure 5.Per-feature accuracy measures (and bootstrapped 95% confidence intervals) of the MFTE on samples of the TEC, the Spoken BNC2014 and
data comparable to the Youth Fiction and Info Teens (for details, see Le Foll
2022c: 277–81)121
Figure 6.Distribution of normalised frequencies of five features across the TEC (histograms) and visualisations of their correlations
(scatterplots)128
Figure 7.Dimension 1 mean scores for disciplines (left) and genre families (right) from Gardner et al. (2019: 655)137
Figure 8.Scree plot of the eigenvalues of the principal components (PCs) for the TEC data141
Figure 9.Snapshots from the 3-D visualisation of the first three dimensions of the multi-dimensional model of intra-textbook
variation142
Figure 10.Scatterplot matrix of all the combinations of the first six dimensions of the model of intra-textbook variation143
Figure 11.Projection of the texts of the TEC on the first and second dimensions of the model of intra-textbook variation144
Figure 12.Graph of the features with the strongest contributions to the first and second dimensions of the model of intra-textbook
variation (see also Table 17)145
Figure 13.Projection of the texts of the TEC on the third and fourth dimensions of the model of intra-textbook variation147
Figure 14.Graph of the features with the strongest contributions to the third and fourth dimensions of the model of intra-textbook
variation148
Figure 15.Projection of the texts of TEC on the third and fourth dimensions with colours and ellipses indicating the proficiency level
of the textbooks (as opposed to register as in Figure 13)149
Figure 16.Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC1 ~ Register + (1|Series))154
Figure 17.Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC2 ~ Register +
Level + Register*Level + (1|Series))157
Figure 18.Estimated PC2 scores across each register and the five textbook proficiency levels159
Figure 19.Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC3 ~ Register +
Level + Register*Level + (1|Series)162
Figure 20.Estimated PC3 scores across each register and the five textbook proficiency levels163
Figure 21.Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC4 ~ Register +
Level + Register*Level + (1|Series))164
Figure 22.Estimated PC4 scores across each register and the five textbook proficiency levels165
Figure 23.Scree plot of the eigenvalues of the PCs for the Textbook English vs. ‘real-world’ English PCA168
Figure 24.Snapshots from the 3-D representation of texts along PC1–PC3169
Figure 25.Scatterplot matrix of combinations of the four dimensions of the model of Textbook English vs. ‘real-world’ English170
Figure 26.Projection of the texts of the three subcorpora of the TEC and the reference corpora on PC1 and PC2171
Figure 27.Graph of the features with the strongest contributions to the first and second dimensions172
Figure 28.Projection of the texts of the three subcorpora of the TEC and the reference corpora on PC3 and PC4175
Figure 29.Projection of the texts of the three subcorpora of the TEC and the reference corpora on PC3 and PC4 with ellipses representing the five
textbook proficiency levels vs. the reference corpora176
Figure 30.Predicted PC3 scores of the texts of the TEC and the reference corpora178
Figure 31.Graph of the features with the strongest contributions to the third and fourth dimensions179
Figure 32.Predicted PC4 scores of the texts of the TEC and the reference corpora181
Figure 33.Predicted PC1 scores of the texts of the TEC and the reference corpora182
Figure 34.Predicted PC2 scores of the texts of the TEC and the reference corpora191
Figure 35.Normalised counts of selected features with salient loadings on PC1 in the Textbook Informative subcorpus (Levels A to E) and the
reference Info Teens corpus (Ref.)192
Figure 36.Word frequency analysis conducted with english-corpora.org (on the basis of COCA
data) of Excerpt (59)220
Figure 37.Part of the ‘word profile’ page of the word lush as generated on english-corpora.org/coca221
Figure 38.Word frequency analysis conducted with english-corpora.org (on the basis of the
COCA) of Excerpt (56)221
Figure 39.Part of the “word profile” page of the word moreover
on english-corpora.org/coca222
Figure 40.Projection of texts on PC1 and PC2 from a random 2/3 split-data analysis of the three subcorpora of the TEC and the three
reference corpora239
Figure 41.Projection of texts on PC3 and PC4 from a random 2/3 split-data analysis of the three subcorpora of the TEC and the three
reference corpora240