I need some ideas for what to do when students miss a lab. I’ve tried having them do the activity before or after school when they return, but that is difficult because most of my students ride the bus.
—Jennifer, Henderson, Nevada
A teacher cannot control student absences, and students should not be punished for missing a class due to illness or a family situation. On the other hand, you plan meaningful activities for students to help them meet the learning goals, and when they miss the activity it affects what they are learning.
Some teachers excuse the student from the activity, but most provide a make-up opportunity or alternate activity. If your main concern is having points to include in a grade, then having the student do a generic report or extra worksheet might suffice. But if the activity supports the planned learning goals, a report or worksheet might not be an adequate substitute for the real thing.
Many teachers provide opportunities for students to make up labs before or after school. But as you mentioned, this is not an option for bus riders or students involved in extra-curricular activities. In a self-contained elementary classroom, you might have more flexibility to accommodate make-ups during the school day. But at the secondary level the only possibilities are study halls or activity periods, when the teacher might be involved with another class. You should not require a student to skip lunch to make up a lab (and eating lunch in the lab is a definite no-no).
Realistically, it’s also hard to keep equipment and supplies set up for an extended time, especially if you teach more than one subject, are ready to move on to a different activity, or share the lab or equipment with other teachers.
If a student misses one day of a multi-day activity, it’s not difficult for them to catch up with their lab team. Perhaps an ad hoc role for a lab team member could be to explain the procedure and share the data when the absent student is back the next day. The absentee would be responsible for completing the assigned report on the activity.
For longer absences, you could consider several possibilities. These could be done outside of the lab and on the students’ own time:

• For each investigation, you could create an alternate assignment on the topic (such as a report or project) that addresses the same learning goals. However, this would require that you plan two separate activities and create rubrics and due dates for the alternate.

• Provide a link to a virtual lab or simulation on the topic. A side benefit here is that other students may appreciate the opportunity for the additional experience.

• Give the student a copy of the question or hypothesis, the procedure, and a data set. Ask the student to draw a picture of the equipment setup, graph and analyze the data, and respond to the question or hypothesis. Model and practice this with the class so students know what to expect if they miss a lab.

• For each activity, ask one group to take photos as they work or record a video of the procedure (using the cameras on cell phones, tablets, or laptops). Print the photos or post the video on the class website so absent students can follow along with the procedure, record the data, and complete the write-up. This may sound like a lot of work, but the graphics do not have to be professional. You only need one presentation per activity, and unless the activity undergoes a drastic change, the presentation can be used again or by other teachers. This may require some practice by student-videographers.

Most students enjoy lab activities and will try not to miss them. If you have many students who typically miss the last class period for athletic events, you could plan the activities for days when there are no events, ask your principal to schedule athletes for an earlier period, or ask the students to come into a class during their study hall (if possible) to join in with another group.
If students are pulled out of your class for special services, perhaps you could talk with that teacher or counselor so if a student must miss a science class, it would be on a day when you don’t have a hands-on investigation scheduled.
 
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