Fig. 1
Fig. 2
Fig. 3
Contractor group × importance level for sources of information and collaborative activities (2007–2009)_
| Other firm/group of firms | Suppliers | Customers | Rival firms | Consultants, private R&D institutions | Universities | |
| Mann–Whitney U | 6,000 | 7,500 | 3,000 | 6,000 | 7,500 | ,000 |
| Wilcoxon W | 12,000 | 13,500 | 9,000 | 12,000 | 13,500 | 6,000 |
| Z | –,775 | ,000 | –1,549 | –,775 | ,000 | –2,366 |
| Asymp. Sig. (two-tailed) | ,439 | 1,000 | ,121 | ,439 | 1,000 | ,018 |
| Public research institutes | Other specialist institutes | Conferences, fairs and exhibitions | Scientific and technical journals | Unions and associations, etc. | ||
| Mann-Whitney U | 4,500 | 4,500 | 1,500 | 1,500 | 3,000 | |
| Wilcoxon W | 10,500 | 10,500 | 7,500 | 7,500 | 9,000 | |
| Z | –1,171 | –1,183 | –1,960 | –1,932 | –1,587 | |
| Asymp. Sig. (2-tailed) | ,242 | ,237 | ,050 | ,053 | ,112 | |
Contractor group × importance level for sources of information and collaborative activities (2004–2006)_
| Other firm/group of firms | Suppliers | Customers | Rival firms | Consultants, private R&D institutions | Universities | |
| Mann–Whitney U | 24,500 | 36,500 | 38,000 | 37,000 | 38,500 | 29,000 |
| Wilcoxon W | 60,500 | 91,500 | 74,000 | 92,000 | 93,500 | 65,000 |
| Z | –1,525 | –,329 | –,198 | –,320 | –,138 | –1,114 |
| Asymp. Sig. (two-tailed) | ,127 | ,742 | ,843 | ,749 | ,890 | ,265 |
| Public research institutes | Other specialist institutes | Conferences, fairs and exhibitions | Scientific and technical journals | Unions and associations, etc. | ||
| Mann–Whitney U | 30,500 | 39,000 | 28,000 | 33,500 | 29,000 | |
| Wilcoxon W | 66,500 | 94,000 | 64,000 | 69,500 | 65,000 | |
| Z | –1,070 | –,102 | –1,109 | –,605 | –1,116 | |
| Asymp. Sig. (two-tailed) | ,285 | ,919 | ,268 | ,545 | ,264 | |