  Many species dream, yet there remain many open research questions in the
study of dreams. The symbolism of dreams and their interpretation is present in
cultures throughout history. Analysis of online data sources for dream
interpretation using network science leads to understanding symbolism in dreams
and their associated meaning. In this study, we introduce dream interpretation
networks for English, Chinese and Arabic that represent different cultures from
various parts of the world. We analyze communities in these networks, finding
that symbols within a community are semantically related. The central nodes in
communities give insight about cultures and symbols in dreams. The community
structure of different networks highlights cultural similarities and
differences. Interconnections between different networks are also identified by
translating symbols from different languages into English. Structural
correlations across networks point out relationships between cultures.
Similarities between network communities are also investigated by analysis of
sentiment in symbol interpretations. We find that interpretations within a
community tend to have similar sentiment. Furthermore, we cluster communities
based on their sentiment, yielding three main categories of positive, negative,
and neutral dream symbols.
