Worm Investigation to Explore Experimental Design

K Hoffman, Mahnomen Public School, Mahnomen, MN based on an activity from MnSTEP Elementary Life Science Institute, and The Truth about Science, NSTA Press, p66


This lesson is one in a series of lessons to help introduce students to science concepts of experimental design, data collection and analysis, and scientific presentation. This lesson would take place following an observation lesson, and prior to work on analyzing results and preparing to share their conclusions.

Learning Goals

Goals: Students will be able to design and write out an experimental plan, anticipate and control for unwanted effects, and make and record quantitative or qualitative observations.
Vocabulary: controlled variables, dependent variable and independent variable

Context for Use

This activity requires that students are able to work in small groups and somewhat independently. I will be doing this as an activity early in the year, and expect that the students will have the necessary group work skills, but may struggle with the unscripted nature because they are not necessarily used to working in that situation.

Subject: Biology
Resource Type: Activities:Lab Activity
Grade Level: Middle (6-8)

Description and Teaching Materials

Materials: 2 petri dishes per group
1 worm per group, with additional worms available
containers with dirt and other worm media
masking tape for labeling
metric rulers
hand lenses
any other equipment that could be used to safely manipulate the worm's environment or that could be used to make observations about the worms

Students will have observations in their notebooks from the previous day with the worms. At the end of the previous day, students would have been asked to consider how they might turn some of their observations into investigable questions. During this lesson, the students will meet to decide which questions they might like to investigate, given whatever time constraint the teacher plans for. I intend to have this lesson take 2 days for the experiment to be completed and data collected.

While the students are discussing, it will be the teachers responsibility to move around the room and help students eliminate ideas that will not work by questioning the students. The students should arrive at a question that answers a question through investigation, rather than a yes/no or research type question.

Students will be allowed to setup their experiments around the room and label them with the tape. The options are really limited only by the time and materials available. Students will be responsible for making and showing the teacher a plan and a format for collecting data prior to beginning the actual experiment. It is expected that the students will replicate the experiment, which can be done multiple times for groups that may do an investigation that is not time intensive.

Following data collection, the students will have a whole group discussion about their data and discuss what that might mean. The teacher will guide this discussion by providing information about how to analyze data as necessary.

Teaching Notes and Tips

This activity is intended for students who are ready to start exploring the use of inquiry on a regular basis. In my classroom that is generally the way that things will go for the year, so this is a non-essential lab that helps them to learn the process.

Students may be frustrated at not being given a procedure to follow, so it is helpful to be ready to ask lots of questions to focus their attention back on what they know and what they might want to know.

Additionally, grouping can be a factor in more open-inquiry type labs like this, as students at very different levels may experience a lot of frustration and lack of positive experiences if they are working together. These may be activities where student ability is considered and more closely matched so that each student gets the most from the experience.


The main way of assessing this lesson for me will be in looking at the reflection in the student notebooks. The goal is to have learned something about experimental design and data collection, so their initial setup may not have been the greatest, but the reflection should show what they have learned about the process.


1. The Nature of Science and Engineering
1. The Practice of Science
1. Science is a way of knowing about the natural world that is characterized by empirical criteria, logical argument and skeptical review.
2. Scientific inquiry uses multiple interrelated processes to investigate questions and propose explanations about the natural world.

References and Resources