Final answer:
The example provided is about automatically grouping a collection of essays written on the US Economy based on similarity or relation using different variables. This task can be achieved using techniques from the field of Natural Language Processing (NLP), specifically Text Clustering or Topic Modeling.
Step-by-step explanation:
The example provided in the question is about the process of automatically grouping a collection of 1000 essays written on the US Economy based on their similarity or relation using different variables such as word frequency, sentence length, and page count. This task can be achieved using techniques from the field of Natural Language Processing (NLP), specifically Text Clustering or Topic Modeling. These techniques involve analyzing the essays' textual data and identifying patterns or common themes to group them together. By applying such methods, researchers can gain insights into the topics and trends discussed within the essays and identify distinct clusters or categories.