Lesson: Methods of population sampling
Do Now: What does it mean to estimate? Take student responses.
State Answer: Estimate means to approximate the size of something. Sampling means to take a small part of a larger amount to gather information. In ecology, it is impossible to count every single organism in a large area, so ecologists use sampling to estimate the size of populations. There are actually four main types of population sampling. They include: Direct observation, indirect observation, sampling and mark-and-recapture.
State: Today’s class will use the jigsaw method to learn about the different ways that ecologists estimate population sizes. You will be assigned one of the four methods and it will be your job to become an expert on that topic. You will then teach the members in your group about the topic. In turn, they will teach you about their topics. In the end, you will be an expert on all four methods of estimating population sizes. (10-12 minutes)
Step 1: Read about your topic silently and take notes. Teacher will copy and cut out the (Jigsaw descriptions handout) Prepare to teach your group about the topic; use pictures, diagrams, etc. to help explain. (5 minutes)
Step 2: You will meet with other experts who have the same topic to make sure that everyone understands what they need to teach. Remember: you group is relying on you, so use this time to clarify anything. (4 minutes)
Step 3: Meet with jigsaw group. Everyone teaches their topic. (Students fill in jigsaw note-taking worksheet) (10 minutes)
Step 4: The entire group takes an open notes quiz (5 minutes)
Step 5: Review quiz as a class (formative assessment). Answer any questions students might have. Handout (Estimating population size HW sheet) (5 minutes)
Students may begin HW until bell. (remainder of class)
Reflection: Jigsaw requires a substantial amount of explanation in the beginning (roles, expectations, etc.) but the students are forced to work together if they want to do well on the formative quiz at the end of the lesson. Jigsaw can be used for many uses, but in science I mainly use it to introduce content with multiple parts, such as layers of the atmosphere, etc.
|Jigsaw notes on estimating population sizes Activity||
|Measuring population size HW sheet Homework||
|population methods jigsaw quiz Assessment||