Flow diagrams are pictorial or word/block displays of relationships between instructional concepts. These displays are accompainied by questions which direct students' attention to specific portions of the diagram and facilitate students' interpretation of the displayed relationships.
The problem addressed by this study was to determine the effects of administering flow diagram-based instructive questions before and after classroom lectures on students' learning of flow diagram-relevant and flow diagram-irrelevant information. The hypotheses predicted that administration of the treatment both before and after classroom lectures would increase students' learning of flow diagram-relevant information but that administration of the treatment before classroom lectures would also decrease students' learning of flow diagram-irrelevant information.
The subjects used in this study were community college students enrolled in a 16-week course in Human Anatomy and Physiology. Multiple choice criterion tests consisting of flow diagram-relevant and irrelevant items were administered to two intact classes after each of seven instructional units. During the first instructional unit each class was introduced to flow diagrams which were discussed during classroom lectures; the criterion test provided a measure of students' abilities to answer flow diagram-relevant and irrelevant test items. During the remaining six instructional units flow diagrams were not discussed during lectures but were administered with instructive questions either before classroom lectures (i.e., BCL condition), after classroom lectures (i.e., ACL condition), or were not administered (i.e., C condition). A counter-balanced nonequivalent control group quasi-experimental design was used because the classes were not randomly constructed and because only two classes were available to compare three treatment conditions. The post-experimental effects of each pair of contrasted conditions were evaluated on two occasions.
The findings of this study showed no difference in flow diagram-relevant or irrelevant mean scores between any pair of conditions except on one occasion when the ACL condition was administered inappropriately. Neither experimental condition resulted in the expected overall increase in students' learning of flow diagram-relevant information. However, when the pre-experimental measure of students' abilities to answer flow diagram-relevant test items was compared to their post-experimental scores using regression analysis (i.e., aptitude-treatment interaction), the BCL and ACL condition;s were found to interact differently with students' abilities. The BCL condition was associated with poor discrimination within post-experimental relevant-category scores while the ACL conditiion was associated with good discrimination. No difference in discrimination was found between any pair of irrelevant-category scores except for the one occasion when the ACL condition was inappropriately administered.
The conclusions of this study are that the BCL conditions' effect on low-ability students was to stimulate them to increase their attention to flow diagram-relevant information presented during classroom lectures while reducing high-ability students' attention to this type of lecture information. The ACL condition provided a useful review of relevant lecture information for high-ability students while this condition interferred with the relevant information low-ability students had learned during lectures. However, these effects were only observed when the BCL and ACL conditions were compared to each other and not when either experimental condition was compared to the control condition.
This study indicates that low-ability students may benefit from the administration of flow diagrams before classroom lectures and that high-ability students may benefit from the administration of flow diagrams after classroom lectures. However, it is recommended that a better predictor of students' abilities to utilize flow diagrams be devised before repeating this study to determine whether or not significant discriminatory differences can be obtained between the experimental and control conditions.