Category Archives: Area and Stream Graphs

Topic Modeling Stream Graphs

The colored streams represent each of the 40 topics of the topic models created for the memcons (top) and the telcons (bottom). The pie graph at the right of each graph shows the relative proportion of topic weight for each month of correspondence. The difference in density between the memcons (which show more activity at the end of Kissinger’s tenure) and the telcons (which show more activity at the beginning) are explained in large part by his promotion to Secretary of State in 1974. Before that time, when he was National Security Advisor, Kissinger utilized telephone conversations to address most of the issues confronting him. After his promotion, he shifted to a more official forum of meetings and memoranda for most of his work.

This interactive diagram can be played back, and various months explored in more detail – for example, the largest spikes in the telcons and memcons correspond to the timing of Kissinger’s promotion to Secretary of State, and to meetings regarding the October 1973 Yom Kippur War and the resultant flurry of diplomatic activity to broker agreements between the combatants in May 1974.

Interactive Topic Model Stream Graphs


Topic Modeling Area Graphs

The capability to go beyond merely counting word frequency to measuring the correlations in frequency between words is a powerful tool for computational historical research. This technique, called ‘topic modeling,’ relies upon complex probabilistic mathematics beyond the capabilities of most historians. Using a variant of MALLET (open-source topic modeling software), I have assembled topic models of the Kissinger collections. The initial results of this process resulted in a 40-category list for both the memcons and telcons collections. By compiling the topic modeling data and graphing each topic’s frequency data into an x/y line/area graph, a contextual, historical timeline emerges for each of the 40 Kissinger memcon and telcon topics. Peaks in the graphs indicate the dates of documents that contain the highest cumulative ‘weighting,’ or relevance, to that respective topic. Immediately, the data graphed on the timeline evokes questions: many of the peaks on the topic graphs synchronize well with related events in the historical record. Examining each topic graph in relation to these historical timelines is in itself a useful exercise for researchers in finding content related to a particular topic.

For example, those interested in reading documents most closely associated with the wars in Indochina and Kissinger’s Paris Peace Conference talks with Le Duc Tho and Xuan Thuy, Chairman Mao and Chou En-lai, the Cambodia Campaign and resulting public outcry in May 1970, the ‘Backchannel’ and SALT talks with Dobrynin, Gromyko, Brezhnev, or other topic areas of Kissinger’s activity can use these graphs to locate the relevant dates and documentation for their topics much more easily than by consulting a traditional index.

Memcons: Interactive Topic Model Area Graphs

Telcons: Interactive Topic Model Area Graphs