Dr. Jones conducted an experiment in which her participants were randomly assigned to memorize a list of abstract words (e. g., freedom) OR a list of concrete words (e. g., flag). Each subject in each word condition was also randomly assigned to one of three memorization technique conditions: (1) silent verbal rehearsal OR (2) aloud verbal rehearsal, OR (3) visual imagery. They then recalled as many words as they could. If the main effect of word list type (abstract words or concrete words) was statistically significant, then: