How can the developments be described both quantitatively and qualitatively?
For the first research issue 11 hypotheses were formulated for the period 1988-1996:
1. The total number of maps increased;
2. The percentage of colour maps increased;
3. Front page maps usually had one column width and were printed in two to four colours;
4. Front page maps usually related to politics, military conflicts and accidents;
5. Front page map sources usually were provided by external news agencies;
6. Maps in additional section usually were larger and more colourful than on inner pages of the first section;
7. Additional section maps usually stood on their own;
8. Newspaper maps were more frequently international than national, regional or local;
9. Quality newspapers had more home-produced maps than popular newspapers;
10. Popular newspapers had more crime maps than quality newspapers;
11. Quality newspapers have higher quality maps than popular newspapers.

These seem to be common sense statements, but even those need to be checked and proved.
The first hypothesis was easy to check. Figure 2 shows the increase of the number of maps, and also shows that the major increase happened between 1988 and 1992.
Figure 2 - Newspaper maps in national newspapers in the Netherlands

The number of colour maps increased likewise, stand alone maps increased and topical maps increased, both absolutely and relatively. Maps on the front page indeed were mostly one column in width and had colour as well. Military conflicts, geopolitics and accidents together accounted for 69% of the front page maps. Elsewhere, in the inner pages they accounted only for 39%, and in the additional sections only for 5%. The percentage of maps provided by external agencies only decreased during the researched period. See also table 1.
Table 1 - Map source vs newspaper section for all 5 newspapers, 1988-1996
Source
Front page
  
Inner pages
  
Additional sections
  
Own production
66
92 %
440
88 %
338
89 %
News agencies
5
7 %
50
10 %
15
4 %
Other sources
1
1 %
8
2 %
22
6 %
Regarding size, the additional sections proved to have over 25% maps with over 3 columns width, whereas this percentage was only 15% for front page maps. Additional section maps proved to have more colour as well. Of the total of 80 large coloured maps (over 3 columns wide) 50 (that is 63%) were inserted in the additional sections. Maps in the additional sections were frequently (28%) unframed, while for maps on the front page (10%) or the inner pages (11%) of the first section this occurred more seldom.
Surprisingly, there has been a relative decrease in the number of international maps. This really means that newspaper maps got more widely accepted, and that for local and regional news the role of the map has been increasingly discovered. See also table 2.
Table 2 - Changes in map scales, 1988-1996
Scale
1988
  
1992
  
1996
  
Local
17
9 %
36
10 %
65
16 %
Regional
44
24 %
93
27 %
137
33 %
National
43
23 %
99
28 %
85
21 %
International
80
44 %
120
35 %
126
31 %
Quality increased as well, see figure 3, with the quality score for the newspapers analysed. The maps were scored for 8 quality aspects, for each of them 2 points could be assigned. So the maximum score for a map would be 16. This was a very tedious procedure to perform for all the maps, as over 470 maps were analysed! It came out that the quality newspapers indeed scored better than the popular press. See also table 3.
Table 3 - Quality score for the 5 national newspapers
Criteria
AD
(n=73)
NRC-H
(n=105)
Telegraaf
(n=118)
Trouw
(n=50)
Volkskrant
(n=81)
Average
(n=427)
Symbol selection
1.5
1.7
1.3
1.5
1.6
1.5
Hierarchy
1.4
1.8
1.3
1.4
1.7
1.5
Functionality base map
1.0
1.2
1.0
1.2
0.9
1.0
Additional text
1.6
1.8
1.7
1.9
1.9
1.8
Relationship map vs text
1.6
1.7
1.7
1.4
1.7
1.6
Availability of map title
0.8
1.0
0.4
0.4
1.1
0.7
Functional use of colour
1.0
1.1
1.0
1.1
1.0
1.0
Uniformity of style
0.8
1.5
0.8
1.5
1.2
1.2
             
Total score
9.7
11.8
9.2
8.9
11.1
10.3
The hypothesis, that because of the urgency to catch the latest news, front page maps would usually be externally produced, was discarded. Only 5% of front page maps had a foreign source, whereas 10% of maps on the inner page were produced externally. In figure 4 the revolution in our newspapers can be seen: how both quality newspapers and popular press, from a dependency on outside sources of over 50%, became nearly self-sufficient. The hypothesis that quality newspapers had less maps on crime was proven as well: they had only 2% crime maps, whereas the popular press had 5% crime maps.
Figure 3 - Quality score of the national newspapers
Figure 4 - Sources of newspaper maps, for quality newspapers and for the popular press
Is there a correlation between the newspaper map theme on the one hand and the map function,
the newspaper section that contained the map and the newspaper map type?