Scientific Skills Flashcards
Reliability of media reports on scientific discoveries is…
Not very good as they usually aren’t peer-reviewed, although, typically, they are based on peer-reviewed data, but this data can be misinterpreted or oversimplified causing bias and inaccuracy.
What economic issue affects experiments?
Budget constraints. Hard to fund experiments without cutting back in other areas.
What social issue arises from research?
Laws based on research affecting lives
What is a personal issue caused by scientific advancement? What other issue may arise from scientific advancements?
Concerns about how something like the construction of a nuclear power plant in your area would affect you, even if you may agree with the use of nuclear energy.
Environmental issues.
What is needed to answer scientific questions?
Data that is of high quality and accurate that supports hypotheses.
Why do some scientific questions remain unanswered?
sometimes data can’t be collected with current technology or there simply might not be enough data to support a theory.
What is an important part of designing investigations?
Ensuring safety
What must every investigation have?
An aim
What does an aim describe?
Purpose of investigation and what you hope to discover/achieve/prove.
What does the scientific method involve?
observing something that isn’t currently explainable by our knowledge, creating a hypothesis to explain the phenomena and then conducting experiments and investigations to prove or disprove the hypothesis.
What happens when a hypothesis is backed by experiments?
It becomes a theory.
What defines reliable data?
Can be reproduced.
What is repeatable data?
when the same person, with the same experiment and equipment can repeat the results of the same experiment multiple times
What is reproducible data?
Different person, similar results.
How many times should results be done for repeatability?
Minimum of three times.
What are the criteria for valid results?
Repeatable, reproducible, answer original question
What must experiments be to ensure validity?
Fair
What is a variable in experiments?
Something that can be changed
What do experiments often change to observe effects?
One variable
What is the independent variable?
Variable you change
What is the dependent variable?
Variable you measure
What are control variables?
Variables that stay the same
What is a control experiment?
You can’t always control variables so sometimes you need a control experiment which is an experiment kept under the same conditions as the rest of the investigation but doesn’t have anything done to it. This is to see what happens when there are no changes.
What is precise data?
when the different data sets are still all very similar and don’t deviate much.
What is resolution in measuring instruments?
Smallest change detectable by equipment
Why must equipment be calibrated?
equipment must be calibrated to the experiments by measuring a known value. If there’s a difference between the measured and known value, you can use this to correct the inaccuracy of your equipment.
What helps correct equipment inaccuracy?
Difference between measured and known values
What reduces random errors?
Repetition and finding the mean
What indicates a systematic error?
Wrong measurement by the same amount every time
What is a zero error?
Systematic error from miscalibrated equipment
What indicates a zero error on a mass balance?
Reading not at zero
What is an anomalous result?
A result that doesn’t fit with the rest
What can be done with known systematic errors?
They are compensable by doing some maths
What is processing data?
Processing data is when you do calculations with your data to make it more useful.
Always calculate what when doing repeats of experiments?
the means
When should you round your answer in physics?
To lowest significant figures
What kind of data do bar charts display?
categoric data (data that comes in distinct categories), discrete data (data that can be counted in chunks, and there are no in-between values), and continuous data, which is numerical data that can have any value within a range.
How to draw bar charts with categoric or discrete data?
Leave gap between bars
Which graph is used for continuous data?
Scatter graph
On which axis do you plot the dependent variable?
Y-axis
On which axis do you plot the independent variable?
X-axis
When is a line graph usually used?
Variable changes with time
What are the three types of correlation?
Positive, negative, none
How do you find the gradient of a curved graph?
by drawing a tangent to the curve, then find the gradient of the tangent.
What is a conversion factor?
Number for unit conversion
What to do when going from a bigger unit to a smaller unit?
Multiply by conversion factor
What to do when going from a smaller unit to a larger unit?
Divide by conversion factor
What do formulas show?
Relationships between variables
What must scientists be careful of when drawing conclusions?
Only from their data
What must a conclusion do?
Match the data and go no further
What is important when writing a conclusion?
Refer back to original aim
What does correlation not equal?
Causation
What are the three reasons for correlation?
Chance, third variable, cause
When can you conclude correlation shows cause?
when all other possible variables have been completely controlled.
What is uncertainty in measurements?
the amount of error your measurements might have.
What does uncertainty measure?
Uncertainty is a measure of how confident you are in the accuracy of your results.
What causes uncertainty?
Random errors, equipment limits.
How can you reduce uncertainty?
Do repeats and get better equipment
Prefix for 10^12?
Tera (T)
Prefix for 10^9?
Giga (G)
Prefix for 10^6?
Mega (M)
Prefix for 1000?
Kilo (k)
Prefix for 0.1?
Deci (d)
Prefix for 0.01?
Centi (c)
Prefix for 0.001?
Milli (m)
Prefix for 10^-6?
Micro (μ)
Prefix for 10^-9?
Nano (n)
How can uncertainty be reduced in experiments?
Better equipment, greater measurements
What is an evaluation in science?
Critical analysis of an investigation
What does an evaluation comment on?
Method and quality
What can be suggested in evaluations?
Improvements
What can be done after drawing conclusions?
Make more predictions
