Day 2

1. Students should receive handouts at the beginning of the hour explaining what they will be doing over the next few weeks. Explain the major steps of the activity and tell students that the purpose of the activity is for them to learn how scientists figure things out. Tell students that they must start to keep all their information for the activity in a journal or a special place in their science notebooks.
   
   
   
2. The main goal for Day 2 is to model the steps of the scientific method. Begin by making a hypothesis to answer the first question.
   
   Teacher: "Based upon your observations yesterday, do you think that ants have a preference for the type of material they collect?"
   
   Write the answers on the board. This basic question lends itself to some very simple hypotheses that students have a good chance of developing. Students are familiar with their own macro environment enough that they can speculate what types of things ants may collect. They also know their own basic human needs, which they will be able to project onto ants.
   
   Student: "The ants are looking for food, other ants, leaves...."
   
   
   
3. Do not confirm or dismiss their answers. Pick one of the explanations and then ask:
   
   "How could we make an experiment to see if this explanation is true?"
   
   Students will give ideas on how to conduct an experiment. If you use the "Looking for leaves" explanation, you should attempt to coerce a concise hypothesis from the students as to what they will need to do to see if the ants are going to a leaf source because they want leaves. A good hypothesis might be:
   
   "If the ants want leaves, they will go to the leaf source, stop, take a piece of leaf, and then return to the nest."
   
   Tell the students to think, within their groups, of where they think the ants are going and to make a statement that they could test to see if their idea is correct. Circulate amongst the students and help when they get stuck. Their greatest problem will be to construct a testable hypothesis based on an idea of where (and why) the ants were going. An untestable statement would be: They are going to the highest point of the biggest tree to get the best view. This isn't testable because we can't go to the top of the highest tree to observe them. After deciding on their individual hypotheses, continue developing the water idea as a group and make a hypothesis similar to the one above. Next, tell the students to spend a few minutes thinking about how exactly they will do the experiment and to write down the steps to their plan. They will likely write some simplified, non-quantifiable plan that will be a reasonable start. While roaming through the groups, you can ask :
   
   • "How many leaves will you use?"
     
   • "Will you place the leaves on the ground or in a container?"
     
   • "How long will you watch to see what happens?"
     
   
   
   
4. Try to make the students be specific. After about five minutes, lead the class in a group discussion geared towards designing an acceptable experimental plan. Go through each step of the plan and come up with something like this:
   • Fill 8 large petri dishes with water, seeds, leaves, branches, dead insects, peanut butter, sugar, or meat.
   • Place each in a depression so that the top of the dish is level with the ground.
   • Spread the dishes an equal distance apart, 2 meters away from the exit hole to the colony.
   • Place a group of students at each petri dish and for 10 minutes count how many ants take the object from the petri dish.
   • Repeat experiment two more times.
   
   
   
5. Five minutes before the end of the hour, discuss how they will take their data. Tell them that they need an organized manner to take, collect, and record their data. Show them a data table that you will use to collect data for the "leaves" hypothesis. The data table would look like this:
   
   

Science Education Connection Department of Biochemistry The University of Arizona Tuesday, April 29, 1997 warder@u.arizona.edu http://biology.arizona.edu/sciconn/lessons/shindelman/ All contents copyright © 1997. All rights reserved.