Working Scientifically - UNFINISHED Flashcards
What is a hypothesis?
An explanation made on the basis of limited evidence as a starting point for further investigation
How do scientists test hypotheses?
They make a prediction based on it and test the prediction by gathering evidence from investigations
How do scientists share their findings?
Peer-reviewed journals and/or at conferences
What is peer-review?
Where other scientists check results and explanations to make sure they are scientific before publishing
Why do scientists peer-review?
It helps detect false claims
What do scientists do once they’ve found out about a hypothesis?
They carry out their own experiments and try to reproduce the original experiment
What are accepted hypotheses called?
Theories
What is a representational model?
A simplified description or picture of what is going on in ‘real life’
What can representational models be used for?
To explain observations and make predictions
What are computational models?
Models that have been formed by a computer to make simulations of complex ‘real life’ processes
What are computational models used for?
When there is a lot of variables to consider
Why would you use a computational model if there is a lot of vaiables?
You can easily change their design to take in new data
Why is it important for scientists to tell the public about their discoveries?
Some discoveries show that humans should change habits or provide ideas for new technology
What are issues with scientific studies in the media?
They aren’t often peer-reviewed, they are often simplified leading to misinterpretation, information may be biased and it may be inaccurate
What are the 4 issues presented by scientific developments?
Economic, social, personal and environmental issues
What economic issues are presented by scientific developments?
Society can’t always afford to do things scientists recommend without cutting back elsewhere
What social issues are presented by scientific developments?
Decisions based on scientific evidence made will have an affect people’s lives e.g. scientists may believe alcohol should be banned to prevent health problems
What personal issues are presented by scientific developments?
Some scientific developments will only affect certain individuals, how would you decide which individuals?
What environmental issues are presented by scientific developments?
Human activity affects the environment but some development could cause environmental problems
Why can’t scientists answer all questions?
Some questions are ethically based, or the data can’t be collected or there isn’t enough data to support a theory
What is a hazard?
Something that could potentially cause harm
What is risk?
The chance that a hazard will cause harm
What needs to be considered with new scientific technology?
The benefits and risks
How do you estimate risk?
By how many times something could happen in a large sample
Why might people underestimate or overestimate risk?
Based on the familiarity of the activity and the effect an activity will have
What are some hazards from experiments?
Microorganisms, chemicals, fire and electricity
What are investigations used for?
To see if there is patterns or relationships between two variables
What three things does evidence need to be?
Repeatable, reproducible and valid
What does ‘repeatable’ mean?
If the same person does an experiment again using the same methods and equipment, they’ll get similar results
What does ‘reproducible’ mean?
If someone else does the experiment, or a different method or piece of equipment is used, the results will be similar
What does it mean if data is ‘reproducible’ and ‘repeatable’?
It’s reliable and scientists are more likely to have confidence in it
How do you make an experiment a fair test?
Control the variables
What is the name of the variable that you change?
The independent variable
What is the name of the variable that you measure?
The dependent variable
What is the name of the variables you keep the same?
The control variables
What is a control experiment?
An experiment that’s kept under the same conditions as the rest of the investigation, but doesn’t have anything done to it
Why isn’t a small sample as good as data based on a large sample?
A sample should represent the whole population
How do you check reliability of data?
Repeat the readings and check the results are similar
How many times should you repeat each reading?
3
What is resolution?
The smallest change a measuring instrument can detect
Why does equipment need to be calibrated?
If it’s not calibrated, it could affect the accuracy of measurements
What are random errors?
Errors caused by random things like human errors in measuring
How do you reduce the chance of random errors?
Taking repeat readings and finding the mean
What is a systematic error?
When a measurement is wrong by the same amount every time
What is a zero error?
Equipment that isn’t zeroed properly
What is an anomalous result?
If you get one result that doesn’t fit in with the others
How do you calculate the mean?
Add the data together and divide by the total number of values
How do you calculate the range?
Find the biggest number and subtract the smallest number
How do you calculate the mode?
The number that appears the most often in a set of data
How do you calculate the median?
Put all the data in order and the middle value is the median
What is the first significant figure?
The first number that isn’t zero
What should you do if your calculation has multiple steps?
Only round the final answer
What 3 types of data can bar charts show?
Categoric data, discrete data and continuos data
What is categoric data?
Data that comes in distinct categories eg flower colour, blood group
What is discrete data?
Data that can be counted in chunks, where there is no inbetween values eg number of people, you can’t have half a person
What is continuous data?
Numerical data that can have any value in a range e.g length or temperature
Should you include a key with a bar chart?
Yes, if there is more than one set of data
On a graph, which axis does the dependent variable go on?
Y-Axis
On a graph, which axis does the independent variable go on?
X-Axis
How should you plot points on a graph?
Use a sharp pencil, make neat little crosses, don’t do dots
What should you always include?
Units and axis labels
What is a line of best fit?
A line that goes through or near as many points as possible, ignoring anomalous points
What is the gradient?
A line/slope which shows you how quickly the dependent variable changes if you change the independent variable
