Jennifer B. Esty
Teaching identification
As was mentioned above, one the ways I intend to teach identification is to have the students look for common, easily recognizable shapes in the different organisms they are studying. The students will then create a key based on the basic shapes. This is a technique that is used in teaching drawing that I think will work well to also identify many different organisms.
The first step in this process is to identify the basic shape of the organism. I will use tree leaves in this example. A sweetgum tree leaf,
Liquidambar styraciflua L.
, looks just like a five pointed star. For this tree, you wouldn't really have to go much beyond this step, but for most other trees you do. So, if a student finds a leaf that is shaped just like a five pointed star, her key will tell her it is probably a sweetgum tree leaf.
The second step is to look in a bit more detail at the leaf shape. So, for example, all elm leaves have a basically oval shape, but so do Dogwood leaves. Ash leaflets have an oval or elliptical shape, too, but the leaf itself is actually compound. The distinction between simple and compound leaves is a good thing to consider at this step in addition to looking for modifications of the basic shape. So, for example, elm leaves are toothed, but dogwood leave are not. Both leaves have a central vein with smaller veins coming off the central vein, but the patterns created by the secondary veins are different. In the elm leaves the secondary veins run straight off the central vein forming a "v" shape. In a dogwood leaf, the secondary veins curve, following the oval shape of the leaf. I recommend the National Audubon Society field guide to Eastern Trees to help illustrate this step.
The next step is to consider texture, overall shape, fruits, flowers and habitat. Once you know that your leaf is probably an elm, the next step is to figure out which elm it is. There are a number of factors to consider in this step. First, is the leaf smooth or rough? Is the leaf the same color on top and below? What sort of bark is on the tree? If you can find fruit or seeds below the tree, are they specific to one species or another. Is the overall shape of the tree unmodified, or can you tell what the natural shape of the tree should be? And, finally, does this tree actually grow in this area and this habitat? These sorts of questions will help a student differentiate one tree from another.
In the case of an animal instead of a plant or tree, the steps are the same, but the questions might be slightly modified. So instead of leaf shape, a student might look at wing and tail shape for a bird or body type and colored markings for a quadruped.
Museum and Zoo strategies
Visiting museums and having speakers come always requires preparation. In fact, the success of the visit really depends on the quality of the preparation. In this case, the students will have particular organisms they are studying for the foodweb project, so the students should have a list of questions about their organisms. However, the preparation goes far beyond that. The teacher should exhaustively explain behavioral expectations and the schedule of the trip with the students as well as why they are going and what they are expected to gain from the trip.
In addition to preparing the students for the trip, the teacher should prepare the museum and zoo staff as well. The teacher should discuss particular topics of interest with the museum and zoo staff prior to the visit to ensure that students get some answers to their questions. The teacher should also arrange an appropriate schedule with the museum and the zoo.
The teacher should also arrange enough adult supervision so that the students can break up into smaller groups to go see particular parts of the museum or zoo which interest them. Part of the museum and zoo experience is an assignment in which the students have to plan a trip to the museum and the zoo with their child. So, it is important that the students be able to explore thoroughly.
Food web project in more detail
The students will have access to the internet at school as well as several field guides, text books, and magazines like National Geographic. From these resources the students will find or draw a picture of their organism. The written paper will contain information about the feeding habits of the organism, their habitat requirements, their reproductive strategies, the threats to their existence, and other similar information. The students will receive a rubric for their project giving the exact requirements and the point values assigned to each piece of the project. The pictures and papers can then be arranged on a wall in the form of a foodweb. The individual piece will be connected by stings or paper arrows or something similar. To ensure a balanced and complete foodweb, the teacher should probably supply a list of organisms for the students to research.
Bioblitz
The concept of a bioblitz is not new, but I have included it here because it is a very useful way to survey populations. A bioblitz is a method of surveying a population without actually counting every single organism in a given area. The surveyors, students in this case are given a small piece of a larger area. The size of the small pieces and their locations will influence the results of the survey as they may reflect local prevalent organisms rather than a true picture of the whole ecosystem. This risk of sampling error can be reduced with a very large number of samples; however, this may not be practical using students. My suggestion is to choose sample sites carefully and have the students come up with some solutions to the problem. Another possibility is to sample the same site over several years to build up a database of many samples, but this approach also has problems. Change over time is inevitable, so that could be a subject of discussion with students if the long term study approach is taken. However, given the greater impractibility of counting every organism in a large forest, this solution is a good way to get a general picture of the ecosystem composition.
The basic system of doing a bioblitz is very simple. Each surveyor or team of surveyors records every relevant organism within the survey area. The varieties of survey areas are pretty much infinite. They can range from a set of squares that border each other and cover the entire site, such as what you might see at an archeological dig, to a scattering of equal area polygons across the site. The most important consideration, though, is to make sure that all the survey areas have contain the same area. Without this basic constant, the results of the individual surveys can not be easily compared.
Elements of a Complete Laboratory Report
Introduction
The introduction explains to the reader why the study being described in the report was done. It introduces the topic of discussion and states the problem or phenomenon being studied. It may also contain background on the subject being studied, references to prior works on the subject, and justifications for the any assumptions made or theories being used in the performance of the study being described in the report.
Hypothesis
The hypothesis contains a proposed answer to the problem or explanation of a phenomenon. It is an initial guess based on the prior knowledge and experiences of the experimenter.
Procedure
This is possibly the most important part of the report. In this section, the actions preformed in the study are described in such a way that the study can be repeated as long as similar conditions can be found to exist. Illustrations sometime accompany this section to more adequately explain complicated experimental setups.
Data
In this section the data that was collected during the study is displayed in labeled tables, photographs, sketches, and other descriptive formats. Calculated results are not found in this section.
Data Analysis and Results
This section contains examples of the calculations done to analyze the data collected during the study. It also contains a basic description of the results of any calculations. For example, "six" is not a result, but "six different species were found in quadrant three" may be considered a proper result. This section frequently contains graphs and charts showing the results of the study.
Discussion of the Results
Results alone do not answer questions. Students must complete the fundamental task of interpreting the results. They must explain the significance of the results. This is frequently the most difficult part of the report for students, but it is essential for their growth as students and as future citizens.
This section of the report is also the place where experimental disasters are reported. Anything that may have affected the accuracy or the precision of the data collected should be explained here. Additionally, the report should describe how the aberrant event may have changed the results; for example, are the data too large, too small, scattered, or something else? All of these considerations go into an estimated experimental error.
Conclusions
The conclusion gives a concise description of the opinion of the student about the question or phenomenon they set out to study. The conclusion is based on the collected data and the data analysis preformed. The reader should also be given an estimate of the accuracy of the conclusions reached based on her estimated experimental error.