Pneumothorax: appearance on lateral chest radiographs

The appearance of pneumothorax on lateral radiographs obtained with the patient erect were reviewed in 100 patients (122 total examinations). A pneumothorax could be seen on the lateral projection in 89% of the examinations (109 of 122). The displaced pleural line was most frequently identified anteriorly or posteriorly and was less commonly identified at the lung apex or in a subpulmonic location. In 11 cases, an air-fluid level was the only recognizable finding of a pneumothorax on the lateral projection. Although in 27% of examinations (32 of 122) the pneumothorax was either not seen (11%) (n = 13) or was a subtle finding (16%) (n = 19), in 14% of examinations (17 of 122) the lateral projection provided helpful information to supplement the posteroanterior projection.     

Comparison of the effect of post-instruction multiple-choice and short-answer tests on delayed retention learning

Background

People forget much of what they learn, therefore students could benefit from learning strategies that yield long-lasting knowledge. Yet surprisingly, little is known about how longterm retention is most efficiently mastered. We studied the value of teacher made in class tests as learning aids and compared two types of teacher-made tests (multiple choice and short-answer tests) with a no test (control) to determine their value as aids to retention learning.

Method

The study was conducted on two separate batches of medical undergraduate students. This study compared two types of tests [multiple choice questions (MCQs) and short answer questions (SAQs)] with a no test (control) group. The investigation involved initial testing at the end of the lecture (post instruction), followed by an unannounced delayed retention test on the same material three weeks later. The unannounced delayed test comprising of MCQs and SAQs on the same material was given three weeks later to all the three groups.

Results

In batch I, the MCQ group had a higher mean delayed retention score of 10.97, followed by the SAQ group (8.42) and the control group (6.71). Analysis of variance (ANOVA) test and least significance difference (LSD) post hoc test revealed statistically significant difference between the means of the three groups. Similar results were obtained for batch II

Conclusion

Classroom testing has a positive effect on retention learning; both short-answer and multiple-choice tests being more effective than no test in promoting delayed retention learning, however, multiple-choice tests are better.