Design a simple causal inference study to evaluate the effect of a new chatbot on customer satisfaction.

Instruction: Outline a study design that could be used to reliably measure the causal impact of implementing a new chatbot on customer satisfaction levels.

Context: This question evaluates the candidate's ability to apply causal inference principles to design a practical study for a real-world scenario. Candidates should consider aspects such as the selection of control and treatment groups, methodologies to minimize bias, and how to measure outcomes effectively.