General knowledge norms: updated and expanded from the Nelson and Narens (1980) norms.

The Nelson and Narens (Journal of Verbal Learning and Verbal Behavior 19:338-368, 1980) general knowledge norms have been valuable to researchers in many fields. However, much has changed over the 32 years since the 1980 norms. For example, in 1980, most people knew the answer to the question "What is the name of the Lone Ranger's Indian sidekick?" (answer: Tonto), whereas in 2012, few people know this answer. Thus, we updated the 1980 norms and expanded them by providing new measures. In particular, we report two new metacognitive measures (confidence judgments and peer judgments) and provide a detailed report of commission errors. Each of these measures will be valuable to researchers, and together they are likely to facilitate future research in a number of fields, such as research investigating memory illusions, metamemory processes, and error correction. The presence of substantial generational shifts from 1980 to 2012 necessitates the use of updated norms.