The article’s 3rd section (“Getting a measure”) is explicitly about alternatives to self reported vividness of experience - citing use of ocular rivalry effect, measuring dilation of pupils when imagining a bright light and sweat responses to a scary scenario. I agree that it’s a difficult thing to make sure people aren’t just experiencing similar things and reporting them differently but there does seem to be effort made to design experiments around differences in how participants form descriptions.
The article’s 3rd section (“Getting a measure”) is explicitly about alternatives to self reported vividness of experience - citing use of ocular rivalry effect, measuring dilation of pupils when imagining a bright light and sweat responses to a scary scenario. I agree that it’s a difficult thing to make sure people aren’t just experiencing similar things and reporting them differently but there does seem to be effort made to design experiments around differences in how participants form descriptions.