How to design in-class problems
Variation in problem types accommodates the needs of different learners, and exposes all students to different ways of learning. Problems can be grouped into one (or more) of the following categories:
- Problems requiring model building and other hands-on activities
- Problems requiring labeled diagrams of a mechanism or process
- Problems requiring synthesis (for example, a concept map)
- Checkpoints (problems providing a short immediate review of main concepts before moving on)
- Analysis-level, context-rich problems
- Case studies (for example, a case study about single nucleotide polymorphisms )
- Problems that build-in a study technique (for example a problem directing students to interpret a textbook figure)
- Problems that replace lecture (students use their reading and reasoning skills to independently learn new material--the "you're not going to get this in lecture" type of problem)
- Problems requiring data analysis, experimental design, or understanding of techniques
- Optional "challenge problems" that allow students who work quickly to continue to benefit from problem solving time
Problem set development requires flexibility on the faculty member's part to respond to student needs. Ongoing formative assessments drive the development of new problems (Tanner and Allen, 2004). Although writing problems is a time consuming effort, you can gradually adopt an in-class problem-solving approach. Each time we teach this course we incorporate less lecture and more problems; it took time to develop a sufficient number of challenging, engaging problems. (See a list of example problems.)
Most of the problems the students solve in groups are ungraded to emphasize the process of learning the material. A secondary advantage is the ability to reuse problems from year to year without advantaging students who could get course material from previous students.
To increase individual accountability students are given a homework assignment prior to each exam. These assignments are based on current research and involve students interpreting data, understanding techniques, and synthesizing concepts. At the beginning of a new unit, students are given a science news article summarizing a current finding that relates to the topics that will be covered. Prior to the exam they are given the homework assignment that contains figures from a research paper related to the science news article they read, as well as some background text summarizing the goals of the paper and key techniques. The students must interpret the figures to answer the questions. The final question asks the students to link all of the concepts covered in the unit and to connect those concepts to this research article. They are asked to do this in a diagram form supported by text. (See an example homework problem.)
Problem keys are essential. In our course, we make the keys available (online) after giving the students time to struggle through the problems on their own (at least two days before the exam). The keys model the problem solving process for the students, and include thorough explanations. The keys provide an opportunity to reteach concepts or to make explicit connections between concepts in response to student performance in class. Keys may include hand drawn figures to mimic student diagrams, as well as computer generated drawings where appropriate. Students may need to be reminded in class to use the answer keys while studying. For an example of a problem key see the RNA processing and Northern blot analysis problem.
The faculty-coached, in-class problem solving approach may require a restructuring of the material in an existing course. Rather than introducing new material primarily through lecture or interactive lecture, in this approach, new material can be presented both by interactive lecture and the problems the students will solve. The problems are not an "add-on" to what is currently being done, but rather can be thought of as a replacement for portions of existing lectures. The function of the lectures is to provide a starting point that allows students to solve the problems.
In designing the shorter, interactive lectures we recognized that covering a topic in class via lecture doesn't automatically mean that students understand and can apply the material. One way we have reduced lecture time is by including fewer historical experiments (although of course we mention key players and their role in science). Instead we incorporate newer experiments into the problems the students solve; this allows us to select a more diverse representation of scientists and exposes the students to current techniques used in biology.
Here are some additional strategies to consider:
- think restructuring, not "add-on"
- assign readings before class that will not be reintroduced in lecture
- convert current homework problems or think-pair-shares into in-class problems
- occasionally have students begin problems in class, finish at home, and allow time for questions the next day
- consider moving some of the problems to lab and linking to lab concepts
How to deal with a large class and many groups
Given a large number of groups in class, and the amount of time spent actively solving problems, it may be useful to hire graduate or undergraduate teaching assistants to supplement faculty interactions during problem solving sessions. Coaching students requires a strong knowledge base, insight into common misconceptions, sensitivity to diversity, and an understanding of group dynamics, skills that may require training for teaching assistants.
The faculty-coached, in-class problem solving approach has not reduced the number of concepts we are able to teach in our course, Genes, Evolution, and Development. To see the concepts we include and how our example problems fit in with the course, we've included a link to the syllabus (Acrobat (PDF) 63kB Oct29 09). The course is part of a two-course introductory series and the second course is Energy Flow in Biological Systems.
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Embedding problem solving in the context of group work requires careful attention to the principles established by K. Heller and P. Heller (2004) and P. Heller and Hollobaugh (1992). As instructors, we:
- assign groups thoughtfully
- set the group size at three students
- assign groups to avoid individuals feeling excluded
- assign new groups throughout the term to foster the sense of community in the class
- provide written guidelines for effective group work
- summarize team-building skills
- list the benefits of group work
- describe the roles often adopted by members of well-functioning groups
- carefully monitor group interactions while solving problems
- intervene when groups are not optimizing their potential
- regroup students in response to particular group situations
We avoid grouping students with widely different working speeds. We have found that students are serious in their approach to the problems, and that even though they are not graded, nearly all students complete nearly all problems. Students can become frustrated if group members either move too quickly for them to follow or hold back their thinking. In our experience, students are more likely to work together productively when they work at a similar speed. For example, we may group three students who tend to work the most quickly, and who do well on exams. Our discussions with this group often include enrichment material not covered in the course. We also group students who struggle on exams; these students benefit from being in the same group and having a faculty member reiterate key points from the lecture.
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Coaching students is probably very similar to what faculty members do during office hours, and individual style will vary from one faculty member to another. Generally speaking, good coaches:
- often respond to a student's question by not answering it; instead, they:
- ask a question in return
- refer back to the text of the problem, and have students look there for help
- tell students to look through their class notes for related material
- remind students the answer to the problem will not be directly stated in their notes
- encourage students when they get frustrated or overwhelmed
- recognize when struggling students need an informal review of lecture material on the spot
- explain to resistant students why particular problems or types of problems are useful to their understanding
- help students stay focused on the problems at hand
- encourage students to be metacognitive, and think about how they arrived at a particular solution
- ensure that each member of the group understands a concept by asking individuals to explain the solution
- challenge students to understand the relevant concepts behind a solution
- help students connect solutions back to earlier topics in the course when appropriate
- provide enrichment to students ready for more of a challenge
- keep track of common misconceptions encountered by multiple groups, and follow up with lecture or additional problems to reinforce the correct concepts
Students can check their understanding through:
Informal interactions when solving problems
- Students find out immediately if their solutions agree with those of their group members.
- Through the process of solving problems, students recognize their points of confusion or their need to review their notes to find information.
- Frequent interaction with faculty allows students to check their understanding.
Exams, quizzes, and graded homework assignments
- A graded homework assignment for each unit helps students synthesize unit concepts.
- A quiz shortly before an exam provides individual accountability and helps students prepare for the exam.
- Multiple exams (including an early, challenging exam) provide multiple opportunities for students to get individualized feedback and respond by changing their study habits.
- Detailed keys for all problems are made available (posted online).
- These important learning tools model the use of labeled diagrams, contextual information, and multiple solutions where appropriate.