Light at night – case study

Teacher Melissa Coton incorporated online citizen science project Globe at Night as part of a year 5/6 unit on light. Here, she reflects on what she and her students learned.

Inspiration for the unit

I chose to use the Globe at Night online citizen science (OCS) project because it linked with our Physical World unit on light. Focusing on light pollution provided a context to apply and deepen our growing knowledge about light.

I was excited that Globe at Night gave students an opportunity to gather their own data, which they could then contribute to a global dataset.

Melissa Coton

As my students were already very interested in astronomy, I thought the context would be highly engaging. I also thought a focus on light pollution would provide lots of opportunities for students to take action as a result of their learning. A huge retirement village development is planned for land at the back of our school field – discussing how the light generated by hundreds of new units could impact on the people and animals in our local area proved to be really engaging.

Intended learning outcomes

The unit focused on developing students’ understanding of the physical properties of light. As we delved deeper into light pollution and its impacts, we also did a lot of learning about how biological processes, such as circadian rhythms, are affected by light and light pollution. To engage with Globe at Night, students needed to be able to identify specific constellations.

Globe at Night also provided a particularly good context to develop students’ science capabilities ‘Gather and interpret data’ and ‘Critique evidence’. We had rich discussions about the limitations of a science project that relies on citizen scientists to contribute data that is based on their personal judgements.

Teacher background

When planning for this unit (2018), I was in my 8th year of teaching. I’ve always been interested in science. I remember loving the hands-on science lessons I experienced at school, and when I became a teacher, I wanted to inspire the same sense of wonder and curiosity that I had experienced.

In 2015, I completed a Postgraduate Certificate in Primary Science Teaching through Open Polytechnic of New Zealand, and in 2016, I participated in the Science Teaching Leadership Programme facilitated by the Royal Society of New Zealand. This was an incredible professional development experience that supported me to develop my own scientific knowledge and my pedagogical practice.

I love teaching science because I have seen its huge potential to engage learners of all levels and backgrounds. I love seeing students’ eyes light up and hearing their enthusiasm and expressions of wonder when they are participating in hands-on investigations and activities.

Class background

This unit was enacted with a class of 28 year 5/6 students. We began to investigate light pollution and use the Globe at Night project after having spent several weeks investigating the properties of light.

Students worked in pairs on Chromebooks to explore the Globe at Night site. At the time we were doing this unit, these devices were very new and students had limited experience using them –- they needed support to develop the digital skills that were needed. Having students signed up to Google Classroom made it very easy to share links to sites and activities with students.

What happened

• Students conducted a series of investigations that helped them develop an understanding of the properties of light.
• We learned about light pollution and its impact on humans and the natural world.
• Students were introduced to citizen science and discussed the pros and cons of scientists using the public to help them conduct their research.
• After a brief introduction, students had time to explore the Globe at Night site and to work in pairs to complete an information treasure hunt.
• We used the Globe at Night site to practise using the light pollution scale to make decisions about the level of light pollution. The disagreements that arose while we were practising making judgements about light pollution provided the context for rich discussions about the limitations of data gathered by individuals using their judgement about levels of light pollution.
• We looked at the data collected by Globe at Night and posed questions.

• For homework, students were asked to use the formal data-gathering protocol set out by Globe at Night to observe the Southern Cross constellation and use the scale to make observations about light pollution in their own neighbourhoods. Unfortunately, the weather was overcast during the designated observation window, and we were not able to contribute to the global dataset.
• We invited a local scientist in to talk to us about light pollution. This was highly engaging and provided an opportunity for students to apply their knowledge about light and light pollution and to get answers for their questions.
• Students compared the dataset from Globe at Night with the Light Pollution Map created from data gathered by satellites. They were asked to decide which dataset they would prefer to use if they were scientists investigating light pollution. This provided a very rich context to develop students’ ability to critique data and to identify the limitations of Globe at Night as a data-gathering platform.
• Students developed the science capability ‘Engage with science’ by writing letters to local businesses, property developers and the council or making signs and posters to raise awareness of the impacts of light pollution and encouraging the school community to reduce light pollution.

What worked well

One of the main successes was the high level of student engagement. Students really enjoyed making their own observations of light pollution and were excited to share the level of light pollution they had seen around their own homes. Globe at Night provided a fantastic interactive activity that supported students to locate constellations and to practise making judgements about the level of light pollution.

Students were able to develop their ability to critique data by examining a second light pollution dataset that came from satellite measurements and comparing it with the Globe at Night data. This supported students to think critically about the reliability of data. We had a rich discussion about the different factors that could account for gaps in data on the Globe at Night site and how data relying on human judgement is not as reliable as data gathered with a calibrated scientific measurement tool.

An activity where the class classified the level of light pollution in photos of the Wellington night sky helped to illustrate the problems associated with using measurements reliant on individual judgements. Students made their own judgements and then shared them with the class and recorded them. It became apparent that, even when using the magnitude guide provided by the Globe at Night project, there was disagreement about the level of light pollution in each photo.

Inviting a scientist who is involved with establishing a dark sky initiative to talk to the class was a hugely engaging element of the unit. It helped to make a link between our local context and a global issue, and students really enjoyed asking questions and finding out about how they can make an impact.

The challenges

The biggest challenge was the weather! Globe at Night requires participants to make an observation of a specific constellation during a set period of time. Unfortunately, adverse weather conditions over the 10-day window made observations almost impossible. As a back-up, we used photos I took of the sky during a brief clear moment at 3am one morning. All students made independent judgements about the magnitude of the stars visible in the photo. This was very helpful in supporting students to develop an understanding of the inherent difficulties associated with collecting data via any method that relies on individual judgement.

Another difficulty was differentiating for a wide range of abilities in reading comprehension, digital literacy and scientific literacy. I found it tricky to pitch the lesson at the appropriate level, and the treasure hunt task I set students relied on a higher level of reading comprehension than many students in the class had. We needed more time to explore the site as a class and ensure that all students understood the concept of citizen science, what the Globe at Night project is trying to achieve and how we would gather data to contribute to its aims.

I think the timeframe for the lessons was too stretched out, and this made it difficult to maintain momentum and student engagement, particularly when the weather interfered with students’ ability to make their own observations.

Problems with the location function on the Chromebooks being disabled meant that students were not able to see constellations specific to the southern hemisphere. Flash Player was also blocked and prevented an interactive running on some devices, which was frustrating for students.

Student learning

Students were able to discuss the physical properties of light and to explain what light pollution is and how it impacts humans, the natural world and the work of astronomical scientists.

This was the first time my students had focused explicitly on critiquing evidence. For many of them, it was a difficult concept to understand. While Globe at Night provided a good platform to explore and discuss data collection and the reliability of evidence, my students will require many more opportunities to critique evidence for me to feel confident that they have mastered the capability at the appropriate level.

Reflecting on using an online citizen science tool

My teaching differed from previous units because we delved deeper into developing a single specific science capability – ‘Critique evidence’.

My intended use of the OCS project evolved a lot during the unit.

Melissa Coton

I felt that the Globe at Night project was strongly suited to supporting students to develop this capability, and my planning and teaching reflected this. We covered protocols and investigation design in a more in-depth manner than I have done previously and in a context that I probably would not have focused on without the support of the OCS platform.

This was the first time my students had focused explicitly on critiquing evidence. For many of them, it was a difficult concept to understand. While Globe at Night provided a good platform to explore and discuss data collection and the reliability of evidence, in a post-unit assessment activity, many students were not able to independently transfer this learning to a new context. They will require more experiences with critiquing evidence in a variety of contexts.

Subsequent to this unit, we have continued to develop the science capability ‘Critique evidence’ by exploring other OCS projects – Orangutan Nest Watch, the Monarch Butterfly Tagging Programme (since 2022 this is no longer being run) and Beluga Bits. This has also helped to develop students’ understanding of OCS projects and the range of different investigations they can be involved with.

Researcher’s comment

This work was carried out as part of the research project Citizen Scientists in the Classroom.

Using Globe at Night as part of the unit about light and light pollution provided opportunities for the students to think about what the Globe at Night data was showing them and what it might mean and to consider whether it told the whole story. Melissa used the data collected over time and across the world to encourage students to notice patterns and to begin to critique what they were seeing. Students began to question and make inferences as to why some regions showed little or no light pollution. Adding a second dataset from satellite images allowed the students to think about the reliability of data collected in different ways.

Melissa’s understanding of the Nature of Science strand and the science capabilities for citizenship meant that she was able to identify and develop rich opportunities for learning through using Globe at Night. Even though weather disrupted her plans, she was able to use her understanding of the capabilities to adapt her teaching and develop even more fruitful learning.

As Melissa points out, her students did not readily transfer the skills they had developed about critiquing the reliability of data to other contexts. This is not surprising – research tells us that students need repeated opportunities in a variety of contexts to think critically about data, what it is telling us and what it is not telling us.