Testing an ethnographic decision tree model on a national sample: Recycling beverage cans

We report here on an ethnographic model of a decision that Americans make regularly: to recycle beverage cans or not. The model was derived from 21 ethnographic interviews and 70 structured interviews in Florida and North Dakota. Ethnographic decision models are not new, but we show here that these models can be tested for both internal and external validity. We test internal validity by comparing the model's predictions systematically to what people say about their own behavior. We test external validity by comparing the predictions of the ethnographic model to those of a representative sample of 386 people across the United States. The original model accounts for about 90% of the reported behaviors, while the national model predicts about 85% of the reported behaviors.