SUGGESTED ANSWER TO QUESTION 16B-1

You learned in this lesson about sharpening and leveling. Secondary sources must do a great deal of sharpening and leveling when summarizing research. In this case, sharpening involves emphasizing details that better illustrate the point the author is trying to make in regard to the research. Leveling, on the other hand, involves de-emphasizing details that the author thinks will confuse readers, or that contradict the point he or she is trying to make. In addition, in summarizing research, secondary sources may report incorrect details about the research.

A good example of this can be seen with textbook discussions of the Little Albert study. You might remember that, when he was about one year of age, Little Albert was conditioned by John Watson and Rosalie Rayner to fear a white rat by pairing the rat with a loud noise (see Chapter 6 and Critical Thinking Lesson 6A). Harris (1979) listed a number of errors found in textbook discussions of this study, such as Albert's age, his name, what he was conditioned to fear, what his fear generalized to, and what happened to Albert after the study was over. Harris asked the following question and then attempted to answer it:

What are the causes of these frequent errors by the authors of undergraduate textbooks? .... Cornwell and Hobbs (1976) suggested that such distortions, if not simply due to overreliance on secondary sources, can be generally seen as authors' attempts to paint the Albert study (and Watson) in a more favorable light and to make it believable to undergraduates. Certainly, many of the common errors are consistent with a brushed-up image of Watson and his work....

A second reason for textbook authors' errors ... is the desire of many of us to make experimental evidence consistent with textbook theories of how organisms should act. According to popular versions of learning theory ..., organisms' conditioning should generalize along simple stimulus dimensions; many textbooks list spurious fear-arousing stimuli (for Albert) that correspond to such dimensions. To illustrate the process of stimulus generalization, Albert is often said to have feared every white, furry object-although he actually showed fear mostly of nonwhite objects (the rabbit, the dog, the sealskin coat, Watson'shair), and did not even fear everything with hair (the observers). But to fit a more simplified view of learning, either new stimuli appear in some texts (e.g., a white rabbit, a white glove) or it is simply asserted that Albert's conditioning generalized to all white and furry (or hairy) stimuli.... Though it might seem as if Albert's fear did generalize to the category of all animate objects with fur (e.g., the rabbit) or short hair (e.g., Watson's head), this is impossible to show conclusively. The only experimental stimuli not fitting this category were the blocks and the observers' hair. Apparently the blocks were a familiar toy (thus not a proper stimulus), and Albert's familiarity with the observers is not known....

As this example illustrates, sharpening and leveling probably are important causes of errors in at least some summaries of research studies. Thus, you should be cautious when reading about a study in a newspaper, magazine, textbook, or other secondary source. You can expect that errors will be made in these summaries, and that important details will be left out or incorrect details added.