Word Frequency
Introduction
In the Lexical Decision activity, you generated results showing that you decide whether a word is really a word faster than if it is a non-word. In doing the Lexical Decision activity, you may have intuitively felt that some real words are decided faster than other real words. In this Word Frequency activity, you will explore this idea objectively with an experimental manipulation. You will generate results showing how accuracy and speed of lexical decisions vary as a function of the frequency with which the words are encountered and used.
Description of Activity
As in the previous Lexical Decision activity, in this activity, your job is to indicate by a button press as quickly and as accurately as possible whether the stimulus you are shown is a word (e.g., “TOMB”) or a non-word (e.g., “SKUGE”). At the beginning of a trial, you will be shown a stimulus that will stay on the screen until you respond. If you see a word, press the “D” key; if it is a non-word, press the “K” key trying to be as fast and accurate as possible. After you make a button press, the next trial will begin. The key manipulation during this experiment is that the actual words vary according to the frequency with which they are used in the English language.
Quantifying Word Frequency
Any discussion of word frequency must include the caveat that what is a “frequent” word for you may not be as frequent a word for your classmate or even your professor and vice versa. Each of us has accumulated through life a different amount of experience with different words, either by reading them or encountering them in conversation or both. That said, there are some ways to quantify whether, on average, some words are more frequent than others. Many internet search engines will now return a small graph below a word’s definition, which includes the number of mentions for the word. Often, this is presented as a graph showing mentions over time. These estimates are gathered from totaling the number of occurrences for the word in the corpus, the collection of written texts in a given language. There are several tools available on the internet to explore yourself in more depth. One is the Ngram Viewer https://books.google.com/ngrams that plots percentage of occurrences in a large text database by time going all the way back to the 1800s. Which word, “cat” or “cube,” do you think is more frequent? Try typing “cat, cube” into the Ngram Viewer and see which word occurs more frequently in the English language text. Did the result match your intuitive prediction?
Word Frequency Effects Across Domains
This activity explores effects of word frequency on lexical decision speed for the visual domain, where words are read and results from others show that decision speed is faster for more frequent words (e.g., “cat”) compared to less frequent words (e.g., “cube”). This suggests that high-frequency words like “cat” are processed more efficiently than low-frequency words like “cube.” Do the same effects occur in the auditory domain where, for example, someone who is congenitally (i.e., born) blind never sees but learns words through conversation alone? The answer is yes if a similar task can be constructed where actual words and nonwords are spoken. What would you predict about other domains, like tactile writing systems such as Braille, where users can read computer screens using refreshable Braille displays? It is likely that word frequency effects on decision speed cross domains.