I have a corpus sliced in three different periods.
I performed the network mapping choosing the ‘custom period’ parameters (custom, three periods, regular), and obtained the three maps for each of them.
I also built a sub-corpus (with a query) for one of the three periods. I mapped that sub-corpus with the same parameters as the overall corpus, but the map for the period that i considered differs than the one of the same period that i produced on the overall map. I saw in the log file that the detected threshold differs, as well as the louvain modularity.
But I cannot understand what is the reason behind it, in the mapping procedure, and also wondering what is methodologically more correct, to separate the three periods of my overall corpus in sub-corpus and map them separately, or map the entire corpus selecting the three custom periods.
Late reply. We hope it will be useful to you anyway!
The simplest way to answer the question is as follows:
- The Dynamic panel (https://docs.cortext.net/analysis-mapping-heterogeneous-networks/mapping-dynamical-analysis-options/) of the Network Mapping script (https://docs.cortext.net/analysis-mapping-heterogeneous-networks/) is designed to track intertemporal changes in the composition of semantic landscapes (if you are working with textual data). Precise calculations are therefore performed for this purpose (see here for some of them: https://docs.cortext.net/analysis-mapping-heterogeneous-networks/mapping/#network-analysis-layout-advanced-settings).
- When a network mapping is computed on a single period, it is isolated from the rest of the periods, without any intertemporal constraints.
But, with a strongly structured semantic landscape, and by refining some parameters (e.g. Find the Optimal Proximity Threshold = no, https://docs.cortext.net/analysis-mapping-heterogeneous-networks/mapping-edges-definition/#find-the-optimal-proximity-threshold), Automatic Intertemporal Threshold and some others in the network analysis layout advanced settings section https://docs.cortext.net/analysis-mapping-heterogeneous-networks/mapping/#network-analysis-layout-advanced-settings …), the two maps should be very close.
I hope it helps.