These three successive maps (one per sample: Jan 7, 1914; Jan 3, 1924; Jan 5, 1934) aim to measure the relative value of space in the Shenbao, according to the "advertising rates" exhibited by the newspaper itself on its first page (1914, 1924) or third page (1934), which depended on four criteria:
- place: situation in the newspaper (front page, last page, middle pages), location on page, neighborhood and its relative value (editorial, headlines, main news);
- time: frequency/number of insertions, duration of the campaign
- size: first measured by the numbers of characters or lines, then by the space (surface/area) covered by the advertisement. This change of measure unit may respond to the gradual importance of images and visual elements, detrimental to texts/textual elements.
- class/type of line: a complex combination of other criteria (length of line, position, etc).
A color has been associated to each category of "space value" to facilitate their identification on the mapped pages.