We have developed a new tool for teaching undergraduate students how to analyze the N₂H⁺ molecular emission line at 93 GHz. Due to its hyperfine structure, the molecular line consists of seven components, and it is commonly used to study the dense molecular cores that lead to star formation. In general, analyses of the molecular line are performed by searching for model parameters (such as the excitation temperature of the molecule and the optical depth of the line) that best fit the observed seven components, which is not an easy task for undergraduate students who are not yet familiar with computer programming. The developed teaching material is designed to be simple, and it can be used with just a ruler and calculator without need for preparing a complex computer program. In this paper, we introduce the teaching tool itself as well as the results of a practical application of the teaching material in a class conducting an astronomy experiment at Tokyo Gakugei University.

The purpose of this paper is to report on mistaken descriptions made in reports on a field exercise by university students taking a school teacher course, regarding the depositional environments of gravel beds, and to discuss the causes of the mistakes. Four cases of the mistakes were found. Case 1: mistaking the rock names of gravel as the name of the beds. Case 2: mistaking the depositional environments of gravel beds with those of the host rocks of gravel. Case 3: mistaking the current environments as the depositional environments of the gravel beds. Case 4: unclear and inappropriate usages of logic in the reports. These four mistakes were most likely caused by an inadequate understanding of the processes of gravel bed formation (Cases 1, 2, and 3); by low awareness regarding the use of accurate words and phrasing (Case 1); and by low awareness regarding writing logical sentences (Case 4). In particular, the percentage of the students who made the mistake shown in Case 2 was 47.3%, showing that their understanding was insufficient regarding the processes of gravel bed formation.