Working Scientifically Flashcards
Theories can involve different types of models- what are the two types of models used when explaining theories? Explain the models:
1) Representational Model- simplified description or picture of what is going on in real life. Like all models, it can be used to explain observations and make predictions. For example, Bohr Model.
2) Computational Models- use computers to make simulations of complex real-life processes, for example, climate change. They are used when there are a lot of different variables (factors that change) to consider. You can easily change their design to take into account new data.
Do models have limitations- why?
- Yes, all models have limitations on what they explain and predict.
- For example, the ball and stick models can be used to show how ions are arranged in an ionic compound.
- One of their limitations include that they don’t show the relative sizes of the ions.
Scientific developments can create issues: what are the economic, social, personal, and environmental issues created with developments in the scientific world?
Economic Issues: Society can’t always afford to do things scientists recommend (e.g. investing in alternative energy sources) without cutting back elsewhere.
Social Issues: Decisions based on scientific evidence affect people- e.g. should fossil fuels be taxed more highly? The effect on people’s lifestyles is unacceptable.
Personal Issues: Some decisions will affect individuals. For Example, someone might support alternative energy but would object if a wind farm was built next to their house.
Environmental Issues: human activity often affects the natural environment. For example, building a dam to produce electricity will change the local habitat so some species might be displaced- but it will also reduce our need for fossil fuels, so will help to reduce climate change.
What are the criteria for good evidence?
- Repeatable- same person does an experiment again using the same methods and equipment, they’ll get similar results.
- Reproducible- someone else does the experiment or a different method or piece of equipment is used, the results will be similar.
**repeatable and reproducible, reliable, and scientists are more likely to have confidence in it. **
-Valid results- both repeatable and reproducible AND they answer to original question; they come from experiments that were designed to be FAIR TEST.
What is the independent variable?
The variable you CHANGE
What is the dependent variable?
The variable you MEASURE
What is the control variable?
The variable you KEEP THE SAME
Why is a bigger sample size better?
Large samples are a better representation of the whole population- it shares many characteristics in the population.
For example, it is more realistic to study a thousand people, with a mixture of ages, gender, and race.
What does the resolution of a measuring equipment mean?
The smallest value a measuring instrument can detect.
What is a RANDOM ERROR?
Human-influenced anomaly
What is a SYSTEMATIC ERROR?
If a measurement is wrong by the same amount every time- repeating the experiment in the case of a systematic error in the exact same way and calculating a mean will not correct it!
What is a ZERO ERROR?
Type of error caused if a systematic error is caused by using equipment that isn’t zeroed properly.
What is an ANOMALOUS RESULT?
A result that doesn’t fit in with the rest of the results or the pattern.
When do you present your data in a bar chart?
If:
- independent variable is categoric (distinct categories)
- independent variable is discrete (can be counted in chunks, no -in-between value)
When do you present your data in a plotted graph?
If:
-both variables are continuous (numerical data can have any value within a range)
