Computer-Assisted Crystallography Education

The primary research objective was to explore the use of computer-assisted learning (CAL) techniques in chemistry education, specifically focusing on the teaching of crystallography and symmetry operations. The study emphasized the use of computer graphics to overcome the challenges of visualizing three-dimensional structures. A key goal was the development of computer software to aid in teaching these complex topics, addressing the limited existing resources in this area. The researchers aimed to create effective educational software accessible to a large number of chemistry students. The software was designed to guide students through selected topics, from initial lecture exposure to final exam revision, employing a teaching strategy that involved computer demonstrations in lectures followed by individual student exploration using the software outside lecture time. This exploration would be partially guided by supplied exercises and drill-and-practice components integrated into the software design.

To evaluate the effectiveness of the CAL approach, the research incorporated a mixed-methods design. A concept difficulty survey was administered to identify areas where students struggled most within the subject matter. This survey was given both initially, to establish a baseline, and later to gauge changes in understanding after the use of the computer software. The study also used attitude surveys before and after the teaching course to understand student opinions about incorporating computers into their education. This comprehensive evaluation strategy provided a thorough assessment of the CAL software's impact on both student comprehension and their attitudes toward computer-aided learning in chemistry. The data collected from both the concept difficulty and attitude surveys aimed to provide insights into not only student learning gains, but also their overall perception and acceptance of the computer-integrated teaching approach.

The development of effective educational software involved careful consideration of various programming languages and their suitability for the project's goals. Several languages were considered, including Applesoft BASIC, GBASIC, and CP/M, each with its own advantages and disadvantages. Applesoft BASIC, while readily available, suffered from limitations in block structuring, hindering the development of complex programs. GBASIC had a significant memory overhead. CP/M, though a superior operating system, required a Z80 coprocessor card, limiting compatibility. PILOT was also explored but proved deficient in precise text formatting and efficient use of disk space. The challenges highlighted the importance of selecting a language that could efficiently handle both the program's complexity and the graphics-intensive nature of the teaching materials. Ultimately, Apple Pascal and UCSD Pascal were chosen due to their superior capabilities in handling large programs and their compatibility with the necessary graphics systems, ensuring that the software could effectively deliver its intended educational value.

The project's success depended on appropriate hardware and software integration. The system requirements included an Apple computer connected to a CRT monitor for each small group of students (7-8 students per computer) and an additional Apple computer interfaced with a printer for the entire class. This setup ensured that sufficient resources were available for students to engage with the software individually, while also allowing for centralized printing of results and outputs. The use of a structured programming language like Pascal significantly aided in the efficient development of large and complex programs, improving the readability and maintainability of the code. The chosen configuration aimed to balance accessibility with the need for a powerful computing environment capable of handling the demands of the graphics-rich educational software. The study's authors highlight the benefits of their choice of programming language and operating system in meeting the overall goals of the project.

A core component of the project was the development of the SGROUP program, designed to provide interactive tutorials on space groups in crystallography. This program aimed to enhance student understanding of the complex three-dimensional relationships inherent in space group theory. SGROUP's functionality included the ability to generate diagrams, allowing students to visualize the arrangement of molecules within the unit cell of a crystal structure. The program facilitated the exploration of the relationship between space groups and molecular arrangements, enabling students to construct diagrams from asymmetric units that correspond to equivalent positions in standard diagrams. This interactive approach made it easier for students to grasp abstract concepts through direct manipulation and visualization, providing a significant improvement over traditional learning methods that relied primarily on static diagrams or three-dimensional models.

To complement the interactive tutorials of SGROUP, the researchers developed the SYMPACK program. This software provided animated demonstrations of elementary crystallographic symmetry operations, including reflection, inversion, glide, and rotation. The use of animation was crucial in enhancing students’ understanding of how these operations transform objects in three-dimensional space, a challenge typically overcome through time-consuming model building. SYMPACK was designed to serve as a lecture demonstration aid, offering teachers a more convenient and flexible alternative to traditional methods such as film or video demonstrations. The advantage of computer-based animation lies in its capacity for real-time adjustment of the sequence and number of demonstrations, making it a highly adaptable tool for educators in the classroom. This dynamic visualization approach was intended to improve student comprehension and engagement compared to static illustrations.

The choice of programming language significantly impacted the software's development and functionality. The researchers explored several options, including Applesoft BASIC, GBASIC, CP/M, PILOT, and ultimately Apple Pascal and UCSD Pascal. Applesoft BASIC, a common language at the time, was found to be inadequate due to its lack of block structuring capabilities, creating difficulties in managing larger programs. GBASIC suffered from high memory overhead, and CP/M required a non-standard Z80 coprocessor card. PILOT, while having some advantages, presented limitations in text formatting and efficient graphics management. The successful implementation using Apple Pascal and UCSD Pascal highlights the importance of selecting programming languages well-suited for managing large programs, and integrating graphics effectively, and ensuring platform compatibility for the target hardware. The adoption of these languages greatly improved the software's overall functionality and facilitated the development of both complex and visually appealing educational tools.

The project emphasized an integrated approach to software design. Instead of developing isolated programs for each aspect of a subject, the researchers attempted to create a series of tutorial programs that followed a logical course of study. This integrated approach aimed to increase the overall teaching effectiveness of the software and to evaluate the potential of this approach in future CAL developments. The emphasis on creating a cohesive and comprehensive learning experience underscores the project’s commitment to providing students with a seamless and effective learning pathway. The results of the project offer valuable insights into how integrated software packages can be designed for computer-aided learning, potentially leading to more comprehensive and effective learning tools in various educational contexts.

A key method for evaluating the effectiveness of the computer-assisted learning (CAL) software was the use of concept difficulty surveys. These surveys were designed to pinpoint areas of greatest difficulty for students within the subject matter of crystallography and symmetry operations. The surveys were administered both before and after students used the CAL software, allowing for a comparison of understanding before and after the intervention. The initial survey established a baseline understanding, and the post-intervention survey gauged the impact of the computer-based learning experience. By comparing the results from both surveys, the researchers could determine the extent to which the software improved students' comprehension of complex crystallographic concepts. The specific items within the surveys are not explicitly detailed but the results were used to show whether there was a significant improvement in student understanding after using the computer program. This method provided a quantitative measure of the effectiveness of the educational software.

In addition to measuring changes in student understanding, the researchers also employed attitude surveys to assess students' perceptions of computer-assisted learning in chemistry. These surveys were administered both before and after the students' interaction with the CAL software, providing a pre- and post-intervention comparison of student attitudes towards using computers in education. The surveys were carefully designed to avoid bias, including both positive and negative statements to ensure that students' responses accurately reflected their genuine opinions. The aim was to ascertain whether the experience of using the computer programs had a positive or negative effect on their attitudes toward using technology for educational purposes within the subject. Analyzing responses to the attitude surveys allowed for a qualitative understanding of the impact of the CAL intervention on student engagement and overall learning experience.

The data collected from both the concept difficulty surveys and the attitude surveys were subjected to thorough analysis to assess the effectiveness of the CAL software. The study mentions correlations were made between specific items from both surveys for a particular class (1984). These correlations investigated the relationship between improved understanding (measured by the concept difficulty survey) and positive attitudes (measured by the attitude survey). The researchers focused on items in the attitude surveys directly related to the use of computers and items in the concept difficulty surveys that showed significant improvements from previous years. These correlations aimed to determine if increased student understanding was associated with a more favorable attitude towards computer-based learning. The results of this analysis provided a comprehensive understanding of the effectiveness of the computer-assisted learning software in improving both student understanding and their overall attitude toward technology in the learning process.

The research incorporated a real-world crystal structure determination to provide students with practical experience and generate potential teaching materials. This approach aimed to bridge the gap between theoretical concepts and practical applications, enhancing the learning experience by illustrating how the principles of crystallography and symmetry operations are used in actual research. The results of this crystal structure determination directly influenced the design and content of the educational software developed in the project. By integrating real-world data and techniques into the software, the project attempted to create a more relevant and engaging learning experience for students, illustrating the practical significance of the theoretical concepts taught. The specific crystal structure studied, its determination methods, and the results obtained are detailed within the original document.

The crystal structure determination involved utilizing standard crystallographic techniques. Specific details regarding the equipment used are mentioned (Nicolet R3m and Syntex diffractometers), radiation sources (Mo Kα), and data collection parameters are provided. The determination methods included Patterson calculations to obtain initial atomic coordinates and difference Fourier maps to locate non-hydrogen atoms. Least-squares refinement techniques were applied to refine atomic positions. The refinement techniques used and software employed (MULTAN80, SHELX) are explicitly stated. The final R-factor values indicate the quality of the refinement. Details on absorption and extinction corrections, the presence of specific atoms (chromium, nitrate groups), and the overall structure are included in the original document, and can be used to better illustrate the actual process and result of the crystal structure determination.