Explain three types of scientific models what is one benefit and one disadvantage of each

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Models to Inform Understanding
Inquiry question 2: What makes scientific models useful?
1. Epidemic models
2. Models of the Universe
3. Atomic models
4. Climate models
Types of Models
Evaluating the effectiveness of a model
Constructing a Model
Some examples of working scientific models made by senior students

Updated April 30, 2018

By John Brennan

A model is a description of natural phenomenon that scientists can use to make predictions. A good model is both as accurate as possible and as simple as possible, which makes it not only powerful but also easy to understand. However, no matter how good they are, models will almost always have limitations.

Most models can't incorporate all the details of complex natural phenomena. For example, when measuring distances around the Earth it's convenient to model the Earth as a sphere, but this doesn't incorporate variations in distance because of mountain ranges, valleys and other topological features the traveler must traverse. Incorporating these additional details would make the model too complex for easy use. Since models must be simple enough that you can use them to make predictions, they often leave out some of the details.

Most models include some approximations as a convenient way to describe something that happens in nature. These approximations are not exact, so predictions based on them tend to be a little bit different from what you actually observe -- close, but not bang on. In quantum mechanics, for example, there are no exact solutions to the Schrodinger equation for atoms from helium onward; exact solutions exist only for hydrogen. Consequently, physicists use approximations for higher elements. These approximations are good, but they are approximations nonetheless.

Sometimes a model can be made more accurate but at the expense of simplicity. In cases like these, the simpler model may actually be superior, because it gives you a way to visualize a process so you can understand it and make predictions about it. In chemistry, for example, structural formulas and ball-and-stick models are unrealistic depictions of molecules; they completely ignore what chemists know from quantum mechanics about the nature of matter at the subatomic level. Nonetheless, they are simple, easy to draw and offer a wealth of insights into molecular structure and properties in a way that's easy to visualize and understand. Consequently, chemists continue to use both structural formulas and ball-and-stick models.

Ultimately, models are subject to some trade-offs. You want as much predictive power as possible. At the same time, you also want the model to be as simple as possible. Nature is indifferent to the human need for simplicity and ease of comprehension, however, and many natural phenomena are complex. Just think, for example, about the chain of biochemical processes that take place merely in order to relay information from the photoreceptors in your eye to the visual cortex of your brain. If you try to incorporate everything that actually happens into a model, it becomes unwieldy and difficult to use. In the end you find that you rely to some degree on approximations and conceptual frameworks that make a process easy to visualize but don't necessarily reflect the true nature of reality.

Updated April 24, 2017

By Serm Murmson

Scientific models approximate trends and processes in the real world. As representations, they are necessarily incomplete and can be disproved. However, models are extremely useful for a number of reasons. First, they provide a way to understand processes that might otherwise be outside the scope of humans. Second, they provide scientists with foundation for further experiments and hypotheses.

Without models, many of the processes in the natural world would remain mysterious. Even though they are partial and potentially flawed, models represent the world in a way that we can understand. For example, the Bohr model of the atom is a significant simplification of the structure of an atom. However, this model helps us conceptualize the atom as a tightly packed nucleus surrounded by orbiting electrons.

Models are crucial to the scientific method. They are never proven correct, once and for all. A model's inconsistencies can be exposed through testing or observations. Then, a new model must be formed. For example, the Ptolemaic model of planetary motion suggested that the planets and sun travel around the Earth. However, this could not account for a number of observed phenomena, such as the phases of Venus. Hence, the Copernican model of the solar system gained prominence.

By Annie

Models:

A model is a simplified description to show the structure or working of an object system or concept. Models may be in the form of practical examples such as an aquarium or terrarium, computer models, or diagrams. Although they are meant or represent real systems, in practice some models require approximation techniques to be used. Also all models have positive and negative attributes.

The advantages of these models are:

they allow scientists to predict and simplify complex systems
inputs can be changed and outcomes examined without having to wait for real events
results can be shown to other scientists and to the public.

Weaknesses of such models are:

they may not be accurate - climate models are hugely complex in terms of numbers of factors involved in atmospheric systems, accuracy is lost in the process of oversimplification
they rely on the expertise of the people making them
different people may interpret them in different ways

some diagram examples of models

1）

Bioavailability and toxicity of selenium nanoparticles

http://homepage.usask.ca/~led917/new-page.php

2）

Environmental science: Nitrogen oxides and tropical agriculture

http://www.nature.com/nature/journal/v392/n6679/full/392866a0.html

Here's a video about the introduction of models.

Page 2

Page 3

Made by Julie:

Holistically: The view that a system has properties that can only be perceived by looking at the inter-relationships of its components, and the functioning of the whole system.

Storages: The stock or reservoir of energy and matter in a system.

Flows: Movement through a system in the form of inputs and outputs. Can be either transfers or transformations.

Steady-state equilibrium: Type of equilibrium where the average condition of the system remains unchanged over time.

Static equilibrium: Where force and reaction are balanced and the properties of the system remains unchanged over time.

Stable: Maintaining equilibrium.

Unstable: Tending strongly to change.

Transfer: Movement that does not involve a change of form or state.

Transformation: Movement that involves a change in form or state.

Sources:

http://www.geography-dictionary.org/

Environmental Systems and Societies Glossary

Scientific models are developed as a means of helping people understand scientific concepts and representing them in a visual medium. Models are used to make predictions. They may include physical and digital models, which can be refined over time by the inclusion of new scientific knowledge.

Students recognise that many scientific models have limitations and are modified as further evidence comes to light. For this reason, scientific models are continually evaluated for accuracy and applicability by the global scientific community through the process of peer review. Students construct and assess their own models, which are generated through practical investigation.

Models to Inform Understanding

Examine the types of models that may be used in science, including:

diagrams
physical replicas
mathematical representations
analogies
computer simulations

Some introductory links

Inquiry question 2: What makes scientific models useful?

There are many different types of models used in science. Most models, however, have certain things that are in common. These include;

help us understand a scientific process or phenomena
based on observations, both quantitative and qualitative
explain relationships between parts in the model
help in creating a prediction related to an unknown aspect of the process or phenomena represented.

A great article from the Science learning hub introduces the scientific model.

Students:

examine the use of scientific models, including but not limited to:

1. Epidemic models

2. Models of the Universe

3. Atomic models

4. Climate models

For each above;

outline how models have been used to illustrate, simplify and represent scientific concepts and processes
explain how scientific models are used to make predictions that are difficult to analyse in the real world due to time frames, size and cost.
assess the effectiveness of models at facilitating the understanding of scientific processes, structures and mathematical relationships through the use of:
- diagrams
- physical replicas
- mathematical representations
- analogies
- computer simulations

evaluate how scientific models draw on a growing body of data from a wide range of disciplines and technologies to refine predictions and test new hypotheses

A model of the universe

Types of Models

Explain why new evidence can challenge the use of existing scientific models and may result in those models being contested and refined or replaced, including but not limited to the development of;

epidemic models
models of the Universe
atomic models
climate models

See information above related to each type.

Evaluating the effectiveness of a model

Models use different “tools” to make them more accessible and often simplify complex phenomena. These include;

diagrams
A model diagram simplifying energy transfers on Earth.
physical replicas

John Stevens locomotive, 1928 replica of 1825 original – Museum of Science and Industry (Chicago)

mathematical representations
The force applied to a body produces a proportional acceleration – Newton second law
analogies

An analogy showing a plant cell compared to a circus

File: CSIRO ScienceImage 11431 Computer model image of a rogue wave smashing into a semisubmersible

More model examples

The Role of Models in a Science activity

Constructing a Model

What should be considered when constructing a model?

Students will be investigating a scientific concept or process that can be represented using a model, by:

planning a model with reference to the scientific literature
writing an annotated bibliography and Harvard reference generator ( see working scientifically section for more information on how to cite your references)
constructing a model using appropriate resources to represent the selected scientific concept
demonstrating how the model could be used to make a prediction
presenting and evaluating the model through peer feedback

Intro to scientific modelling