Open Learning Initiative

Statics is a sophomore level engineering course, offered in all mechanical and civil engineering programs. We study methods of quantifying the forces between bodies, for example parts of mechanical, structural, and biological systems.

Features

• Course Structure
  
• Exposition
• Problem Solving Procedures
  
• Assessment of Problem Solving and Conceptual Learning
  

Course Structure

The OLI Engineering Statics course consists of a series of units, each containing a set of modules. Each module is broken into a series of pages.

Each page is devoted to a carefully articulated learning objective that is independently assessable. From any page of the course, students have access to the learning objectives for the current module by clicking on the objectives button in the top or bottom of the navigation bar.

Figure 1 Illustrating course structure.

To promote the integration of knowledge addressed in this course and to help students retain “the big picture”, the major conceptual themes of Statics are articulated in the course introduction and revisited regularly.

Most of the learning objectives are addressed through three highly interactive elements:

• Exposition – Relevant concepts, skills, and methods are explained.
• Problem Solving Procedures – Because Statics requires solving problems as well as understanding concepts, larger tasks have been carefully dissected, and addressed as individual procedural steps.
• Assessment of Problem Solving and Conceptual Learning – To see whether concepts were grasped and procedures mastered, students are presented with assessments that capture the goals of the learning objective at the end of each page. The student can then determine whether to continue or if further study of previous material is warranted.

Exposition

Relevant concepts, skills and methods are explained. Besides words and static images, which are typical of textbooks, basic content is presented through the following additional means.

Non-interactive simulations, often involving motion, can be initiated by the student, and might be viewed as analogous to in-class demonstrations. After each such simulation, there is always a short “Observation”: one or two sentences to ensure that the student takes away the intended lesson of the simulation. The extensive use of motion to convey basic concepts in Statics is consistent with the authors’ pedagogical philosophy of making forces and their effects visible.

In interactive guided simulations, students adjust parameters and see their effects (what-if analysis). These are often initiated by a question which the student is supposed to answer. These simulations are also followed up with a succinct observation.

The course seeks to take advantage of digital images of relevant artifacts and video clips of mechanisms, to the extent that they solidify material presented and explain its range of application.

Also, consistent with the authors’ pedagogical philosophy of focusing initially on forces associated with manipulating simple objects, students are often guided to manipulate simple objects to uncover relevant lessons.

To help students review the key points, each page, which is devoted to a specific learning objective, ends with a brief summary called “To Sum Up”.

Figure 2 Guided Simulation motivating the discovery that forces on a body independently control the translational and rotational tendencies, and that both must be zero for equilibrium.

Figure 3 Illustrating use of digital images/manipulating simple objects.

Problem Solving Procedures

Since Statics is a subject that requires solving problems as well as understanding concepts, larger tasks have been carefully dissected, and addressed as individual procedural steps. To help students learn such procedures, we use several approaches.

First, we explain the procedure in straight text, often with a worked-out example.

Second, we demonstrate the application of the procedure with a “Walkthrough” (an animation combining voice and graphics that walks the student through an example of the procedure). Such an approach is viewed as particularly effective, since it engages both aural (hearing) and visual pathways, diminishing the mental load on each. This is particularly the case when we want the student to make appropriate connections between words and evolving graphics.

Students themselves first engage in problem solving procedures in “Learn By Doing” (LBD) exercises. These are computer-tutors in which students can practice the new skill as they receive detailed hints and feedback.

Most tutors offer the student the option of asking for a Hint at each step. Successive hints often have increasing degrees of specificity, for example:

• The first hint reminds the student of the relevant underlying idea or principle.
• The second hint links the general idea to the details of the problem at hand.
• The final hint virtually gives the answer away, but explains how one would arrive at the answer.

Figure 4 Walkthrough describing procedure of determining center of gravity for composite body.

Figure 5 Tutor on calculating moments using perpendicular and parallel components, illustrating hints in verbal and graphical form.

Assessment of Problem Solving and Conceptual Learning

At the end of each page, students have a chance to see whether concepts were grasped and procedures mastered, through computer-tutors that are referred to as “Did I Get This?” (DIGT). Although they are similar in form, LBD tutors can be viewed as offering formative assessment, while DIGT tutors serve as summative assessment. Such assessments capture the goals of the learning objective. The student can then determine whether further study of previous material is warranted.
Wrong answers at each phase provoke feedback. Depending on the question, feedback for an incorrect answer may be generic ("That's not right") or specific and tailored to each incorrect answer, particularly when a likely diagnosis of the error can be made.

In some tutors, multiple versions of a problem can be generated with altered parameters; these enable students to practice a procedure multiple times if needed.
If the student cannot independently answer the main question of a problem correctly, some tutors feature scaffolding: the student is taken through a series of sub-steps and at any time can go back and try to answer the main question.
Assessment of conceptual learning often involves the posing of questions that require a one or two-sentence written answer from the student. After the student submits an answer, the correct answer appears and the student may compare them. “Submit and Compare” exercises seek to foster critical thinking on the part of the student.

Figure 6 On resolving and summing forces, illustrating scaffolding. (See video demonstration)

Figure 7 On illustrating scaffolding/submit and compare.