Investigating Phenomenon that Change Slowly

One of the most enjoyable investigations that I recently observed was during science time in a pre-K classroom. After the teacher reminded students to wash their hands and not to squeeze the little creatures, the excitement built as each student was given a worm to study. The students, holding out their hands as if they were waiting for a prize, immediately began to smile and ask questions.

This investigation was part of a sustained inquiry that began earlier in August when students were introduced to a tub of shredded newspapers, sliced potatoes, and a small container of worms. Using hand lenses and watch glasses to help them see the details, students had the opportunity to set up the worms’ home and to observe them from time to time. Their task was to watch and record how the worms changed during the ten months of the school year.

The first lesson taught students how to handle the worms while making observations. They discussed how worms in the natural world are not used to being handled by children and how it is important for students to wash their hands to keep from giving the worms any germs that might be harmful.

The pre-K students also learned how to measure the length of each worm by using the lengths of their little finger as a nonstandard unit of measurement. The children were able to determine the worms were about one finger long. Their teacher took pictures of the worms while they were lined up with students’ little fingers to record the length. They also counted the number of worms being introduced to the tub and recorded the number on a wall chart.

During their first few observations, students talked about the worms’ home. They discussed what the worms needed in order to survive as living organisms. The students knew that worms needed moisture, oxygen, food, and a place to live; they also learned that these worms needed warmth and darkness. On the days the worms were observed they added additional food scraps, such as banana peels, coffee grounds, and eggshells. They also checked to ensure the moisture in the tub felt no more than that of a squeezed-out sponge. If it was too dry, they added water.

In later sessions, students talked about the anatomy of the worm as they were trying to figure out which end was the head and which was the tail. They watched as it moved across their hands and on the table top in a wiggly motion. Several students used their fingers and arms to replicate how the worms moved. Students were encouraged to feel the surface of the worms so that they could feel the small hairs that helped worms to move through the soil and across their hands.

Over the course of the school year, students observed that some of the worms were longer and shorter than their little finger. When they counted the number of worms in the tub, they found that there were sometimes twice as many more worms than the number they found the time before. Several students began to predict that the increasing number of worms were because the adult worms were having baby worms. They concluded that the larger worms were the adults and the smaller worms were their babies.

Sustained inquiry investigations such as these are appropriate for all grade levels and can include all areas of science: life, earth, space, and physical science.

Life science inquiries can range from the yearlong observation of fish, class pets and the metamorphosis of many insects, to observing germinating seeds and growing plants and trees in the schoolyard. These studies of living organisms are fertile ground for long-term observations that allow for data collection and analysis to compare the changes that occur due to growth.

Sustained inquiry is also of value when studying changes in the natural world outside the classroom. The daily changes in the weather, including temperature, precipitation, cloud-cover, and wind, provide ample data for analysis on a daily basis as well as data for the long range changes that occur with the seasons.

Long-term space science observations, such as the apparent movement of the Sun, should be included when studying objects in the sky. By measuring the length of shadows throughout the day and the differences in shadows made by stationary objects, such as the flagpole, that change with the seasons of the year, it provides rich opportunities for data collection and analysis. This study could include student-led discussions and argumentation about predictions from their long-term study. Observations of the changes in the Moon over a period of a month are key to understanding moon phases and the effects of the Earth-Moon-Sun system.

Earth system sustained inquiry investigations can include measuring the rate of erosion in local creeks or in the school yard, changes in the pH and temperature of a compost pile as it matures, and changes to the surface of the earth, including succession, that occur after land has been cleared due to a natural catastrophic event or a man-made change due to construction projects.

The benefits of sustained inquiry are numerous and authentic to the practices of scientists. Students learn how to make their observations, record them as data, analyze their data, and enter into discussions as they draw conclusions about the evidence of the changes they are observing. Students are then able to connect their conclusions to the science concepts they are studying.

I would like to invite you to visit and look through our resources about sustained inquiry to help you learn how to implement this type of investigation in your classroom. There are several videos and resources that offer a few ideas you might want to try in order to promote the authentic practices of scientists for yourself and for your students.

Have you had similar experiences? As comments to the blog this month, share with us your ideas and experiences with bringing new strategies into the science classroom and in preparing a student-centered learning environment! I hope Talley’s Take becomes a place where you and others can get great ideas about being a STEM teacher.


Terry Talley, Ed.D.

STEMcoach in Action!

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