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More than 10 years ago, culminating tasks were a very important curriculum component for teachers in the province of Ontario, Canada. Science teachers in all three major subjects (biology, chemistry, and physics) were told by our Ministry of Education to develop culminating tasks for each unit of study. Each unit of study…imagine the time and energy needed to carry out tasks such as these — in addition to trying to fit the entire curriculum into one semester!

A culminating task is a summative task that effectively ties together the learning outcomes of a particular unit or course of study. Anyone who has assigned students with a culminating task likely understands that it is an excellent way to assess the cumulative knowledge of students and allow students to develop confidence in their knowledge of the material learned. However, in recent years, culminating tasks within the curriculum in Ontario have switched in their area of focus. It seems that many teachers have either abandoned culminating tasks altogether (as they are very time-consuming and stressful to students) or, like myself, have moved to an end-of-course culminating task that tries to encompass as much of the content as possible within a multi-day lab exam.

Speaking from experience, when I’ve assigned a culminating task after each unit, I’ve found the workload on students to be too much. We would simultaneously be wrapping up a research assignment, doing a lab write-up, and preparing for the unit test. Adding a culminating task to the mix was just too much for students. These tasks also ate up valuable teaching days. However, these directives had come from our Ministry of Education, so I still tried. Unfortunately, I found that instead of trying to implement a culminating task after each unit, an end-of-course culminating task eased the stress on both students and myself.

Are culminating tasks a worthwhile and manageable task for high school chemistry students? Yes, they are! A culminating task is very appropriate in high school and is perfectly partnered with the chemistry curriculum. Some examples of successful quantitative tasks that I have used as a lab-based final assessment, in addition to the written exam, include:

• Identifying Unknown Solution: Students are given a 30mL sample of an unknown solution along with a list of possibilities. Students identify and determine the molar concentration of their solution.
• Five Reactions of Copper: Students begin with a specific mass of pure copper, place it through five different reactions, and (ideally) recover the same initial mass of copper at the end of the experiment. A great quantitative lab!
• Analysis of Limestone: Students determine the percent composition of calcium carbonate (CaCO₃) in a sample of limestone chip.
• Analysis of Aspirin: Students determine the percentage of acetylsalicylic acid present in an aspirin tablet.

Throughout the semester, students conduct many lab experiments in which they often learn new techniques and work collaboratively with others to perform the experiment. A culminating task, however, allows students to perform independently and draw on the knowledge and skills they have learned from each individual lab experiment completed previously.

What better subject than chemistry for students to showcase their hands-on and applied learning? A culminating task can allow students to put into action all the wonderful chemistry they have learned over the semester. To name just a few examples, they can apply new knowledge and laboratory skills gained from lessons, conduct lab techniques and calculations with accuracy and precision, and practice critical thinking and in-depth error analysis. It is almost a disservice to not have a final, quality-based culminating task for chemistry students that can address such an all-encompassing list of course expectations.

How to coach students for a culminating task

Quality assessment activities, such as culminating tasks, are challenges that students need to work toward and prepare for over an entire semester. This is not a task that should be sprung onto students two weeks before they are to carry one out. In fact, good quality culminating tasks should be introduced in prior grade levels. In order to accomplish this, a task such as a simple reactivity of metals activity can be performed. This task encompasses all the fundamental concepts that the students have learned in the introductory chemistry unit — matter, elements, physical and chemical properties, physical and chemical changes, valence electrons, bonding, and reactivity of metal elements.

Students are set up to work either individually or in pairs to perform the lab activity. After the data is collected, the students then return to their seats and perform the rest of the task themselves, independently. Depending on the class level and type of students, you might or might not permit them to use their notes.

In a senior high school or AP chemistry class, students are taking a full class in the subject (having been exposed to a unit of chemistry for the past two years of junior science). Throughout this course in chemistry, teachers will be teaching proper lab skills and techniques, and exposing students to a wide variety of equipment. Teachers already coach the students toward a task every semester just by doing daily lessons and activities. When planning to use a culminating task in your teaching, another step to consider is coaching students for the actual task itself, and overcoming the anxiety that often comes with it.

The setup of a culminating task

From my experience in our senior courses, there may be an end-of-course culminating task that will allow students to work in pairs for the lab work, but most often the tasks are carried out so that the students perform them completely independently (for example, carrying out a more complex chemical reaction and quantitatively analyzing a product). The task is given to them toward the end of the semester and the students are given 30-60 minutes to read over the booklet that has been put together for them, complete with an overview, rules or limitations of the task, the lab procedure, and assessment questions. I prefer to have the students write and do all their work in the lab exam booklet. No notes or scraps of paper are used at all.

I allow students two days for the lab work and then another period or two to work on the lab write up or assessment questions. The booklets do not go home at all — all work is done in class. Our teachers feel strongly about this task, because it showcases the students’ own work and knowledge, not what their friends or the internet knows. This is easy to monitor within the classroom setting and we allow the students to access the booklets at lunch or after school if they feel they need extra processing time. Students can, of course, discuss the task outside of class with their peers, but ultimately they are forced to communicate their thoughts and ideas on their own.

A successful culminating task is not thrown together quickly by the teacher. It is carefully thought out and planned. It is prepared for in every lab activity and task carried out with students starting on day one of the course. Teachers are constantly coaching students to develop skills necessary for them to be successful at this task.

A few weeks prior to the culminating task, teachers should carry out a ‘practice run’ with students. A simple concentration of solutions lab could be used, where the students are given a sample of a known solution and then must determine the percentage and molar concentration in an inquiry-based experiment.

Once the students develop a procedure with a partner, they then carry out the procedure and answer the discussion questions on their own. This gives them some insight as to what they can expect when the final task is administered a few weeks later. A good ‘dry run’ task helps to alleviate anxiety and stress for the students and helps them build confidence. When they can successfully carry out a simpler task, they will feel more confident in taking on the larger task.

Benefits of Culminating Tasks

• Demonstrate skills learned

Figure 1. Filtration from the analysis of limestone culminating task performed by my students.

Teachers have spent time and energy teaching students proper lab skills and techniques. Students know how to properly read graduated cylinders, use a burette, set up a filtration apparatus, and use a volumetric pipette and burette. They can now use all of these skills collectively in a good quality culminating task.

Choose a multi-step lab procedure that students will be able to do and that will allow them to show the good techniques and skills they have acquired. Pick a lab that requires two classes to be carried out. As this is the final lab project, it should be substantial, new to the students, but still use concepts and skills familiar to them.

• Critical thinking and literacy skills

Science is truly the most wonderful, all-encompassing subject of numeracy and literacy. Chemistry, in particular, blends these two areas beautifully. Students take qualitative and quantitative data and explain their results both numerically and with detailed explanation. Referring back to their data (whether it is good or not) and properly explaining the results obtained takes good critical thinking and excellent literacy skills. As they have been coached by teachers all along the course, this is the ultimate expression of skills learned. This is where teachers can sit back and feel pride for the journey these students have taken toward scientific literacy.

• Build confidence

Wisely choose your culminating task. Pick a procedure that the students have not performed but that uses lab practices taught to the students over the semester. Tasks such as these can cause students to experience some anxiety and stress. While these are normal feelings toward any type of summative evaluation, students need to learn how to manage these emotions and build confidence within themselves when approached with challenging assessments. A properly chosen task will give students positive feelings toward a culminating task. Too often students can become worked up over the anticipation of the task.

Once students read the procedure and carry out the lab, they realize that they are completely capable of carrying out the task. If the teacher has coached and prepared the students well, they will be so pleased and satisfied with their performance. Students generally love lab work, and what better way to assess them than with a quality culminating task? It truly is a wonderful sight to see students realize they can successfully carry out these tasks themselves!

If a culminating task seems overwhelming to you, start small and pick a task that is manageable for both you and your students. Working with another colleague is helpful as you can share responsibilities in the preparation of the document and all the materials/equipment that needs to be organized. From my experience, students really enjoy the task (once it is over!) and feel a sense of pride in their accomplishments. It is also nice, as a teacher, to see the students perform lab skills and analysis that you have taught and passed onto them. I encourage you to add a lab component such as this to your course, if you don’t already.

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