The English spaced compound word database.

Compound words combine existing words to form a new concept. Spaced compound words represent one form of compound words in which the orthographic space is preserved between the two constituent words (e.g., coffee table). While recent research has mostly focused on unspaced compound words, spaced compound words offer important insight into the cognitive processes that support lexical retrieval and comprehension. Critically, whether readers process spaced compound words as single lexical units has important implications for how these items are stored and accessed in memory. To support future research, we developed the English Spaced Compound Word Database, wherein we collected familiarity, age-of-acquisition (AoA), and semantic transparency (ST) ratings for 1,162 spaced compound words. We conducted correlational analyses to compare these ratings across words, as well as across previously collected data on compound words' constituents. These analyses revealed a strong association overall between familiarity ratings and AoA, as well as familiarity and ST. When examining the relationship between ratings and the characteristics of a compound word's constituents, we found a strong relationship between frequency, AoA, and structural simplicity (i.e., number of characters, syllables, morphemes, and lexical similarity) within all three rating tasks. These findings provide a basis for testing future theoretical models of lexical processing and reading.