WHAT IS CLUSTER ANALYSIS?
Cluster analysis, as a method of rhetorical criticism, is a process critics can use to evaluate the perspectives and worldviews of a person communicating something. The term “cluster” is used because we can learn a lot about what someone is thinking (even subconsciously) by “clustering” key words and symbols they use in a communication with other words and symbols that are used in proximity or relation to the key words. The method is attributed to late rhetorician Kenneth Burke, who sought to understand how people think and what motivated them to action. Burke used the concept of terministic screens to describe the terms, vocabulary, symbols, and other communication devices that people use to describe a concept; thus, as we evaluate the word choice, symbolism, colors, and other communicative devices in any given artifact (“artifacts” are any communication piece, from a speech to a novel to a song, but cluster analyses are usually better for larger documents–not great for billboards, etc.), we can peer through a filtered screen of sorts to understand a person’s worldview, or where they may be coming from when communicating.
Effective cluster analyses follow three steps:
- Identifying key terms
- Charting clusters around those key terms
- Explaining the artifact
Review the graphic here for guidance in doing a cluster analysis or read the larger text below. To see how to actually write the full rhetorical analysis/report, see the rhetorical criticisms overview page.
STEP 1: IDENTIFY KEY TERMS
Study your artifact(s) for key terms. To do this, you are looking for either frequency or intensity of certain words or phrases. (Typically, It’s good to keep your key terms to five or six.) Find the words that are repeated the most (frequency) and then find the words that have the greatest impact (intensity). Highlight those terms.
STEP 2: CHART CLUSTERS
While looking at your key terms, you can see words and phrases that “cluster” around each term, meaning they are either in close proximity to the key term or they are an effect of the key term. Highlight the clusters around each term and then chart them out.
What is you are discovering in this process is relationships. If a key word is “goal” for example, you start noticing how the rhetor sees goals—how they impact people, what causes them, their greater effects, and so forth.
STEP 3: EXPLAIN THE ARTIFACT
With several key terms listed and their relevant clusters charted, you can paint a picture about the artifact itself and the rhetor’s worldview about certain topics. Based on your analysis, you are in a position to find patterns and links between terms and ideas. associating ideas within the rhetor’s mind. You may also consider looking at how opposing terms are used and identify any conflicts or disturbances in the text.