Teacher Notes
- Research Question
- Background Information
- Research Hypothesis
- Research Design
- Data Collection
- Analysis of Data
Research Question
Each student should receive a "Research Booklet" prior to the investigation. This constitutes their Research Notebook. A Research Notebook is what real scientists use to record data, and we want students to learn the proper techniques for doing GOOD science research. They should NOT be given loose sheets of paper. The entire notebook must be reviewed and understood by students before they begin their investigation. On the first page, they will read a letter that contains the specific research question. The letter is designed to improve their interest in the investigation. Their research question is:
"Do Barn Owls in North Carolina eat the same type of food as the Barn Owls that once lived in the restored area of Washington?"
While the question is fictitious, the context is real. Translocations of species from one location to another are at times made in order to improve the biodiversity of an ecosystem. However, such inoculations of new species into an area have to be done thoughtfully so that the project is successful. I have provided an 8-page summary on the reintroduction of the gray wolf, Canis lupus, into Yellowstone National Park as a example to illustrate this conservation strategy.
Wolf Reintroduction into Yellowstone National Park
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Background Informational Study (This is essential!)
Students should not leap into tearing apart owl pellets. Before they state their hypothesis, students must first learn relevant background information which in this study includes owl feeding behavior, barn owl ecology and conservation ecology as it relates to animal translocations. If they do not, then their hypothesis will generally be nothing more than a wild guess. Background knowledge will ALSO help them to (a) understand what they are doing as they do it and (b) properly evaluate their data. Students often view conducting background informational research as wasted time and just want to get started with their pellet dissection. However, remind them that it is very important to understand what they are doing and why they are doing it. Soldiers going into battle have a much greater chance of succeeding if they are well trained and have a good battle plan that they understand.
Remember our major goal is to teach students how to do good science research. The owl pellet study is the vehicle for accomplishing this aim.
So where do they get the proper age-appropriate background information?
1. Use books (for young readers) that have credible information about owl ecology and behavior, as well as specific information on barn owls. Click the owl puppet image below.
2. Create a short presentation. Here is a brief presentation that describes the reintroduction of gray wolves into Yellowstone National Park in the 1990s. A number of the pictures that I have shown are digital images that you can acquire on the Internet, since they are in the public domain. Click the wolf image below.
3. Provide students with informational fact sheets that you prepare. Click the Barn Owl image below.
In the Research Booklet (Page 2), I have a series of questions that the students are asked to answer. The purpose of these questions is to gain some insight into whether or not the young students have acquired some understanding of appropriate background information. The correct answers are YES for all the questions except #8 which is NO.
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Hypothesis
A hypothesis is a tentative explanation of what each student believes the answer will be before they conduct the investigation. Based on their background knowledge, have them formulate a hypothesis. In the Owl Pellet Research Booklet, I help young students to learn what a hypothesis is by giving them two hypotheses. They select one of them. By recalling the background information they acquired, each student can make an informed decision. Strive to have each student write an explanation of why they selected their hypothesis since this will give you some indication of what type of thinking went into their choice.
Instructional Tip! It is not uncommon for young students to think they must go back, after they collect data, and change their answer if need be. Therefore, you will notice that the Research Booklet assures them it is okay to be wrong.
A note about predictions
At times you may encounter a reference source that states that your students should formulate a prediction. A prediction is NOT a hypothesis. With young students, I avoid this term so as not to confuse them. However, here is a brief explanation of what a prediction is. Basically, it is an "if...than" statement. In other words, if the hypothesis that is selected is correct, then when the following procedure (you briefly state the procedure) is implemented, the outcome will be (you state the outcome). The reason the term is confusing to many students (and adults) is that it requires that you know what you are going to do in order to formulate it. As yet, students do not know the research procedure so how can they write a prediction? If you absolutely want to use the term, then have them formulate a prediction after they understand what they are doing. Alternatively, you can do what I did for their hypothesis and write several predictions and then have them select one.
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Research Procedures and Design
So far you have been doing a good science inquiry study since the students have a very narrow research question to solve. They have to acquire background information, and they have to formulate a hypothesis. All of this takes time, but it is time well spent! Think how much they now know, and they haven't even started dissecting the pellets.
So far, you have been a facilitator in that you have been guiding their learning. Now you have to travel down two highways so to speak. The first highway requires that you tell them the procedure they will follow. They must understand it completely before they begin. The second highway involves giving them some opportunity to participate in the design of the study. Of course, you could ignore doing this, but if you do then you relinquish the chance to build the confidence and competence of your students to conduct scientific research.
Research Procedures
This you give them!
1. Safety - Identify ALL safety concerns ahead of time and have a plan in place to address each one. It is your responsibility to ensure that the research study is conducted safely so think the entire study out carefully. Review all safety procedures with the students and make certain they really understand them. Here are some important considerations:
(a) Students must wear protective gloves but be extremely careful of using latex since some students may be allergic to latex.
(b) Buy the owl pellets from a company that has treated the pellets to remove microbes. Do not use pellets that were freshly obtained without being sterilized.
(c) Students must never put their fingers in their mouths or elsewhere onto their body while doing the investigation.
(d) At the end of the activity, students must wash their hands thoroughly with soap and water.
(e) Do not let the students use sharp instruments to pull the pellets apart. They can use wooden probes, plastic tweezers and even their glove-covered fingers to tease open the pellets.
(f) Cover the entire work table with newspaper. At the end of the study, fold up the papers with the dissected pellets and discard into trash bags. Immediately disinfect the desk or table tops. Collect the dissecting tools from the students and thoroughly wash and disinfect them.
Remember that real scientists always strive to conduct their research safely. Thus, teaching your students the importance of safety is not wasted time. Carolina Biological Supply Company has written up some very good safety guidelines to follow.
Instructional Tip! With young elementary school students, I have often used a mentoring strategy. A few older students (e.g., 8th graders) are first taught the lesson. They then are assigned to a group of young students. The older students oversee the safety and conduct of the study. They provide the individualized attention to ensure that students understand what they are doing. They absolutely do not tell the young students step-by-step what to do. In other words, they function as facilitators. Furthermore, it is a great educational experience for these older students.
2. Pellets - This study requires that students have two sets of pellets. Each set represents a certain geographical area. You, therefore, have two options. Buy pellets from a Biological Supply Company that provides pellets from different geographical areas (e.g., Ward's Biological Supply Company) or acquire one set and split them into two groups.
3. Students may work in teams. Teams of two works well since this will enable everyone to be doing something. Place labels (one label says 'Washington' and one label says 'North Carolina' at each work station so students do not mix up pellets. Each team should dissect a minimum of one pellet from each geographic location. Keep one pellet on one side and another on the other side of the table. Alternatively, you could distribute one state at a time so there is less chance of mixing up the results. [However, this approach takes more time.]
When the teams start, they can place the pellet in a cup of warm water for about 1 - 2 minutes. This loosens the fur and facilitates removing the bones.
4. Amount of time for the study – This will depend on a number of factors. How many pellets each team dissects. How capable your students are at manipulating pellets and then identifying the bony contents. How detailed the identification will be. You should consider blocking off 1 - 2 hours for the actual dissection work.
Research Design
Students can help with this!
Remember, we want the students to become empowered to be able to design a research study. So let them work through this part as much as possible. However, let them know what constraints they will be dealing with. For example, time may be a constraint, so they have to know how much time they will have to do the study. The number of pellets that they will be able to dissect may also be a limiting factor so again tell them the maximum number allowable per team.
The students are NOT doing an experiment but rather an observational study, since they are describing what they observe. Experiments are done when you want to determine what causes something to happen. Thus, they do not have to establish a controlled investigation. However, there are some key components to conducting a good observational study that you should review with them and, when possible, get their input.
a. What is the physical entity that they are studying?
Answer: They should tell you Barn Owl pellets from two geographical areas of the United States – Washington and North Carolina.
b. What are they measuring?
Answer: They should tell you that they are measuring the number of different organisms present in each pellet as determined by the skulls. Age and ability level of your students will define how detailed the identification can be. Because of the targeted age level (grades 3 - 5) for this investigation, I have only included the following general taxonomic categories:
• Rat
• Mouse
• Shrew
• Mole
Please keep in mind that these four terms are NOT the names of species but rather general terms that designate a variety of specific species. A real scientist would make every effort to identify the skulls to the species level. In fact, some companies that sell Barn Owl pellets include taxonomic identification guides to enable students to try to identify the skulls in detail. Older students may be challenged to use such guides. With younger students, I recommend focusing on the broad categories that I listed above. This will prove to be a big challenge for them.
Be aware that the lower jaw (mandible) will be separated from the skull. In fact, this bone will most likely be separated into two halves. Therefore, tell them that one organism = one skull (that includes the upper teeth) plus two parts of the lower jaw.
Skull identification sheets are included in the Research Booklet. They must be reviewed ahead of time so students thoroughly understand what they are looking for. Students must be able to understand the identification characteristics for each mammalian group.
c. How many pellets will they be using?
Answer: They should tell you at least one from each state. Depending on the number of pellets that you buy, you may allow them to increase their sample size for each geographic area.
You should discuss with them the fact that scientists try to increase their sample size in order to determine what they discover represents a true picture of what is happening. For example, if someone walked into your classroom and gave a test to only one student, would that tell them how smart all the students in the class were? Obviously not! Thus, increasing the sample size has good scientific merit. So ask the students how can they do this if they are limited to just one or two pellets per team.
Answer: Someone should be able to tell you that they can use data for all the teams. The limitation to this is that they must rely on other teams to collect good data. From my experience, most students opt to use group data. However, I have on occasion encountered teams that would not accept the data from other teams because they did not feel it was collected properly (e.g., the other team members were not serious enough, obvious errors were observed such as a team stating that they found 25 skulls in one pellet).
Instructional Tip! If students consistently give you the wrong answer then do NOT keep fishing for the right one. Stop and tell them the answer. Then have them repeat it several times. If you do not, then it is likely that they will continue to remember the wrong answer(s) that they give.
Discussing these topics at this time improves the study and prepares your students for the discussions that will occur when they analyze the data. Therefore, it is time well spent!
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Data Collection
Now the students are ready to begin. Again, you should have blocked off enough time to start and finish the dissections of the pellets. Caution students to go slowly and carefully so that they do not destroy skeletal material. This is not a contest to see how fast they can get done. They should push the fur off to the side of their work area and place the skulls in another location. Once again, each skull should have a right and left lower jaw (mandible). Place two mandibles with each skull by using size and specific characteristics.
Warning! Young children often make skeletal identification mistakes. I have seen some of them inadvertently counting other disarticulated bones (e.g., vertebrae, leg bones) as skulls. [See the articulated skeleton of a shrew.] Therefore, it is important that each team member verifies the work of the other team member, and that you double check their data. [For example, if a team claims to have counted 35 skulls in one pellet, then they mistakenly counted other bones as skulls.]
Carefully identify the skulls and place the number of skulls found into the data sheets. Be careful! Students generally find only one or a few skulls in a pellet. Team members should try to come to an agreement as to the identity of the skulls. However, since each student has a Research Booklet, if they can't agree about the identity of a skull (e.g., is it a rat skull or mouse skull), then they should record what they believe is the answer in their booklet.
Warning! Students sometimes record data in the wrong location. Watch to make certain that the data for each geographical location is recorded on the correct page of their Research Booklet.
Instructional tip! Place two charts on the blackboard or whiteboard so students can record group data. This means designating each team by a number. However, use of group data should be a team decision.
Instructional tip! Keep moving around the room while they are conducting their dissections. You are a facilitator. Keep watching that they are doing the study safely and accurately. If you are using older students as mentors, then this task will be considerably easier.
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Data Analysis
Once the study is completed, the work area should be immediately cleaned up, and students should wash the table and their hands.
Each team must now analyze the data. You should see some really spirited debate between students as to what the data means. It is a joy to watch young children passionately arguing as to exactly what the data is saying.
At a teacher-training workshop, where we reviewed this owl pellet lesson plan, I had an elementary school teacher say to me "What is the correct answer?" My response was "There is none, since you have no way of knowing how many skulls will be located by the students and what the taxonomic categories will be. As long as the study was conducted carefully, and every effort was made to achieve accuracy with identification, then the answer is based on what they discover and the way they interpret the data. Different students may have different interpretations for the same data." (Read the next paragraph.)
Scientists use statistical analysis (that involve complex mathematical equations) to analyze data they collect. Obviously, your young students do not have this luxury. They will have to look at the data for each geographical location and decide as to what it means. If your students are capable, then have them graph the data. A graph is a visual picture of the data, and it can help them with their interpretation. [ A graph on page 9 of the Research Booklet will help students analyze their data.] Some students may feel that the information collected indicates that the Barn Owls from the two geographical areas eat the same type of food. Others may feel that the data isn't strong enough to warrant such an interpretation. Consider that 9 justices of the United States Supreme Court hear a case and may split their decision (e.g., 5 to 4). However, they all listened to the same information.
In their Research Notebook, they should clearly state what they concluded and why. If a student really understands the background information associated with the research investigation, then they will have a much easier time explaining what the data means.
Communicating the Analysis
Scientists always communicate their finding by writing reports in scientific journals and giving presentations at meetings. Each team should designate a team member who will stand up and state what their team decided and why. If there is a division among the team members, then that should be articulated as well. Ultimately, each team member has placed into their Research Notebook, their answer and the reason for their answer.
The entire class can now vote in order to see what the overall conclusion was. I have seen this go both ways. The important point here is that the students are acting like real scientists, since they are making objective decisions based on the scientific evidence.
Instructional tip! Collect their Research Notebooks and grade them for neatness, thoroughness and the intellectual thought that went into the recording and analyzing the data. Remember that there is no right or wrong answer. Furthermore, consider giving them a grade for the quality of their effort throughout this entire research study.
Final Comments:
Remember that science is a process of discovery as to how the world works. The outcome of these discoveries represents the content knowledge of science. All too often, schools focus on just having students memorize this content, and either ignore the process or merely have students slavishly follow step-by-step investigations that are given to them (a.k.a. "cookbook" science). However, the joy students experience in studying science does not come from obediently following these two approaches. It comes from gaining the competence AND confidence to properly do science on their own. In other words, being able to do science inquiry. This Barn Owl investigation is but one example of how to help your students begin that journey of discovery. If you are willing to give them this opportunity, then you will be amazed at how much they will enjoy the trip and even more astounded at where you find this new skill will take them as they come to love science.
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