por Fei Gao hace 15 años
249
CEP806 Group 3 (Oct 5)
High school biology classes have traditionally included frog dissections as a key component of learning. This hands-on activity is viewed as essential for understanding scientific processes.
por Fei Gao hace 15 años
249
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I give my 7th grade students the opporutnity to do frog dissections towards the end of the year. This opportunity is provided for two main reasons:
1. It is high interest (which is good for the end of the year)
2. It is in someways a culminating activity for our "human body unit" (so various organs and such are relevant and familiar)
I actually use a "hybrid" model containing simulations and the "real" thing. My main purpose for incorporating the simulation is for a few reasons:
1. It gets kids used to the "guts" and what they are getting into (this is important for squeemish 7th graders).
2. They have actual "practice" making the initial cuts and pinning (saving some instructional time).
3. It provides pictures so that students can "see" what they are going to be looking for...(organs, etc.)
I give students a day in the computer to explore. In addition, I provide links on my website for students to explore further.
Over the past 3 years, I have found that students become much better prepared to do the "real" thing. However, the frog simulations lack the ability to go further. For example, if a student wants to look at the actual eye ball or brain, he or she cannot do that in a simulation. Hands on dissection and instruction allows students (and me) to be naturally curious. Whereas, simulations are much more methodical in nature, not allowing for further exploration (and the possibility of getting squirted when cutting out the eye ball :) )
It is always interesting to see what kids roll up their sleeves and dive into the dissection, while others feel oppressed that their teacher is "forcing" them to do such a gross activity.
The "real" dissection lasts around 2 class periods (45 minutes each). Students are required to list various organs that they see and "group" them according to the different systems.
Group Discussion: Simulated vs. Actual Frogs
One of the standard activities of high school biology is the frog dissection. This activity has endured for many decades and dissections of this sort are considered to be absolutely central to learning what science is all about. With the advent of computer simulations, teachers now have a choice of doing actual and/or simulated dissections.
In this discussion, you are to consider the pros and cons of simulated frog dissections.
Before starting, you need to try a few simulated frog dissections. Here are three suggestions.
Froguts. Select the frog dissection demonstration and complete it in its entirety (5-10 minutes).
The "Froggy" Project from the Lawrence Berkeley National Lab for an example of an actual virtual dissection. Spend time exploring the "Virtual Frog Dissection Kit" as well as some of the other resources and information. (5-10 minutes)
"Net Frog" from the University of Virginia. This is another virtual dissection website. It requires a fast Internet connection because it has audio and video clips. Also, it is a bit more graphic (dissections by their nature are graphic) and you may not want to explore this site while eating lunch. (15 minutes)
After you have explored the virtual learning expeiences, you may enter the discussion. Please focus the discussion on the following question:
What important aspect of a good science education is gained or lost in doing simulated, rather than an actual, frog dissections?
The purpose of this discussion is to get you to consider more carefully the nature of learning experiences. In particular, we say we prefer "hands-on" or "real" experience, but we are too often quite inarticulate about exactly what it is about these kinds of experiences that makes them compelling. What do we mean by "real" or "hands-on" and why are they important to learning. Hopefully, this discussion will encourage you to become more sophisticated in your understanding of this issue.
It's nice just to have the experiment at a click of a button. Less prep is good, plus kids could do it at home or on their own if they miss classs, and more...
Pros
Cost of Dissection Software vs Physical Dissections
Simulated frogs are cost effective as opposed to purchasing actual frogs for students to dissect. In fact, DoDEA does not approve of school funds spent on live dissections for students under ninth grade. At least allowing students the change to manipulate the simulated frogs allows students to experience a virtual simulation. Something is better than nothing!
Flexibility in the Science Lab
Students can perform the same dissection multiple times in order to get a better understanding of the subject matter. Simulated frogs can be used in conjunction with traditional dissection or it can be used in place of it. Some parents or students object to the dissection of animals. In addition, some people object to dissecting actual animals due to animal rights. Using simulated frogs removes that obstacle.
Lab Safety
Actual physical dissections in a lab require the use of sharp instruments and harsh chemicals that can lead to injuries; especially in students are not following directions. In addition, some schools do not have adequate labs to perform dissections. Furthermore, some students on IEPs may not be allowed to handle sharp objects. Virtual simulations illuminate all of those obstacles.
Enhance the Science Curriculum
Using simulated frogs is a terrific way to engage gifted and unmotivated students who may otherwise be bored. The ideal situation is to use virtual science labs such as FroGuts with a smartboard. Students can actually touch the board with their finger and maneuver the tools in a more interactive modality.
Students are definitely engaged when they have to "do" something. Although they are not really cutting and removing organs, they get a sense for what is like. Many kids grow up in the virtual reality, so they may see it as an extremely valuable (and beneficial) experience. Even though it may seem artificial to us, I think students reach a level of believability that provides for an effective educational experience.
As a 7th grade teacher (who does frog dissections) I have found that the internet simulations prepare most students for the "guts" that they are going to see. AND, it prepares them for how to cut open the frog and pin it, etc.
I have personally used the 3rd simulation and http://www.mhhe.com/biosci/genbio/virtual_labs/BL_16/BL_16.html
I think I have used another, but I don't have that info with me at the moment...
A few pros...
1. Great tool for review! As part of our Biology curriculum we dissect fetal pigs and then give students a lab practical (in which students ID organs on the specimens). For a few days before the practical we review the organs as a class using my video projector and some of the virtual dissection sites.
2. Useful for homebound or queasy students. I love dissections, but I realize for some of my students it's the worst lab of the year. Students can use these sites and still learn the material.
3. On a logistical note, the virtual dissections are much cheaper and cleaner!
These simulations aren't very exciting- I remember boiology class. The anticipation and highlight for the year was all about cutting up pigs or cats or frogs grasshoppers or whatever. And, no, I am not psychologically sick, I jst thought that part was cool.
I couldn't get one of the frog simsto work on my home computer. You definitely need to make sure your computrs can hack it before planning a leson on sims,
Lack of technology infrastructure to support quick internet speed. Kids get frustrated if a web site does not upload quickly enough. Both Erica and Chuck mention lack of exploration and special relationships. I think that moderation is the key. Virtual simulations such as FroGuts cannot replace actual dissections. There needs to be a combination of live dissection with virtual dissection. However, young students (4-6 graders) can use the virtual simulation activity to increase their readiness level for the live dissection once they reach high school.
In general, these simulations are "recipes." They give step by step instructions of what to do. Additionally, they do not allow for deviation and exploration. Whereas, the "real" simulation provides numerous opportunities to dive deeper and it encourages natural curiosity...which the simulations cannot simulate.
"Froggy" is in no way interesting or engaging.
Students would have to "unclick" items to make this simulation worth anything.
Thoughts:
1. The frog does not even look real. Students are not dissecting a neon frog. The simulation is far from real.
2.There are no instructions for the actual dissection (cutting and pinning, etc.).
A few cons...
1. Lack of spatial relationships. You just can't get in there and move organs around on a website like you can with the real thing. I think a lot of misconceptions about the human body can be dispelled during actual dissections because students can see the interconnectedness and relationships between various organs and organ systems.
2. Not as engaging. Students are so accustomed to surfing the Internet, I wonder if the virtual dissection becomes just another website rather than a true learning tool.
3. No anomalies. The virtual sites most often use the typical structure of an organism's body. It seems like we get at least one odd specimen in every shipment of organisms. After the initial surprise, I like to use that specimen as a teaching tool. Last year our Anatomy teacher received a pregnant cat--it was all the students could talk about that week.
As with any teaching strategy there are pros and cons of virtual dissections.
