Both Tony and Kim expressed errors on their final interview that did not appear on their essay exam. This result was consistent for all 88 students. The interview about student drawings revealed almost twice as many different kinds of errors as the other data sources (). Thirty-two different errors were expressed by at least 2 of 88 students (–). The interview detected all but one of the gas transport/utilization errors. In contrast, the essay exam detected only four of six blood pathway errors, four of five blood vessel errors, five of seven gas exchange errors, none of the six gas transport/utilization errors, and three of eight lung function errors. The learning activities were sensitive for detecting different errors in one or two categories. For example, the pretest drawing revealed over half of the blood pathway errors and lung function errors but almost none of the gas exchange or transport/utilization errors. The peer review essay revealed over half of the pathway errors and most of the gas exchange errors but very few of the blood vessel, gas utilization, or lung function errors. The debate revealed most of the blood pathway and blood vessel errors but almost none of the lung function errors.
The drawing interview was more effective than the essay exam for revealing erroneous ideas. For every category, the portion of students with correct or erroneous ideas was significantly different between the essay exam and the final interview (). The final interviews and drawings (last column of –) generally exposed a high frequency of students with erroneous ideas even though the interview was conducted after the three class sessions had been completed, when progress in learning would be expected. In many cases, erroneous ideas were firmly held even after instruction that exposed the most frequent errors to scrutiny and discussion. The most common blood pathway, blood vessel, and lung function errors were uncovered by the pretest drawing (, , and , first column), whereas the peer review essay best revealed the error that carbon dioxide is converted to oxygen (expressed by about 1 of 4 students; , second column). During the classroom debate, it became apparent that a number of students thought the lungs remove all of the carbon dioxide or that gas exchange is an active process (, third column) or that oxygen is a fuel and waste carbon dioxide turns lungs black (, third column). Several erroneous ideas persisted over time, across different learning activities, and were robustly held in spite of confrontation (–). These include the round trip blood pathway (), problems with the term “vein” (), the idea of carbon dioxide conversion to oxygen (), and other problems about gas diffusion ().
Peer Review Essay - HERO AND LEANDER - FINAL - SlideShare
Students first completed the pretest drawing with their written explanation of human blood circulation and lung function (). The topics were then studied in a human body unit during 1 wk of the semester (three 2-h class sessions). Because of time constraints, students in three of the five sections wrote and then peer reviewed essays about blood circulation. Students in the other two sections debated opposing assertions about models of blood circulation. After instruction and feedback, all students were assessed by an essay exam where they explained how blood circulation facilitates exchange between the body and the external environment. Part of the final exam was an interview using the same diagram prompt from the pretest (). The drawing helped students gather their thoughts and gave them confidence. They had plenty of time to draw and write about the blood pathway and lung function before they were individually interviewed about their drawings in a quiet room.